FSC100 Notes PDF

FSC100 Lecture Notes **Week 1-LEC 1:** Slide 1: Law and Science - Philosophical foundation of criminal justice: - protect the innocent - ensure the truth emerges (role of forensic officer not working for anyone but the scientific fact emerges) - Law defines certain behaviours as cr...

FSC100 Lecture Notes **Week 1-LEC 1:** Slide 1: Law and Science - Philosophical foundation of criminal justice: - protect the innocent - ensure the truth emerges (role of forensic officer not working for anyone but the scientific fact emerges) - Law defines certain behaviours as criminal - It provides framework of regulations, and - Determines standard of evidence required for\ prosecution - Both law and science work within the criminal justice system; differ in goals and methods Slide 2: Law and Science - Law: - Goal: -Relies on the adversarial system and arguments to resolve conflict -Truth decided by the trier of fact (judge of jury) -Outcome based - Science: - Goal: -Describe workings of the natural world -Relies on the scientific method and refinement of hypotheses to validate ideas -What truth is/whether truth can be determined dependent on available evidence -Justification based -science is the need to describe something that's happening (rely on scientific method) -law uses scientific fact to argue \- -forensic derived from the Latin "forensic" -public debate or discussion; judicial connotation \- Science derived from Latin word for knowledge -relates to scientific method -forensic methodologies draw from wide range of disciplines -anything can be evidence -as a result, "forensic science" is hard to define -broadly, forensic science is the application of science to law Slide 3: Defining Forensic Science - "Forensic" derived from the Latin '*forensis*' - Science derived from Latin word for knowledge - Relates to scientific method - Forensic methodologies draw from wide range of disciplines - Anything can be evidence - As a result, "forensic science" is hard to define - Broadly, forensic science is the application of science to law "The application of scientific knowledge and techniques to legal matters." (Bell, 2008) -Linkage and timeline, utilizing new technologies, how something was planned out, the path of the perpetrator, ex. bloody shoe prints-can assume there's a point A and point B, the \# of suspects -QUESTION: -"What are some ways in which forensic science may assist in criminal investigations? -Often criminals aren't intelligent (can be due to nerves) -In the past: -ex. eyewitness testimony -easy for bias to sneak into this process -Extraction DNA wasn't introduced until the 1980's (1981), Forensic science is new Slide 4: Why is Forensic Science Important? - Science brings about objectivity - Not influenced by emotion, bias, or opinion - In the past, convictions were based on subjective evidence - Today, scientific evidence allows criminal investigations to be more objective Slide 5: The Forensic Expert - Forensic scientist must remain an unbiased advocate for the objective facts - May be called upon to serve as expert witness - Only declare an expert witness by a judge - Lay witness: what was heard, saw, done, or experienced -No special training or technical knowledge - Expert witness: may offer opinion on the work that was done and significance of the findings -No special training or technical knowledge -Testimony must be factual (not-opinion based) -Hearsay means opinion based Slide 5: The Forensic Expert \*A serious task - Opinions of expert witness may weigh heavily on the outcome of a case - Criteria for being declared or accepted as an expert witness: - Witness is of sound and unquestioned integrity - Witness is sufficiently trained and experienced - Science or technology presented meets criteria of acceptance - Science or technology presented meets criteria of acceptance -Peer review -Testing and validation -Rate of error -General acceptance - Base opinions/conclusions on facts established by reliable methods -Innocence project -if testing is accurate (rate of error) Slide 6: The Scientific Method - Science adheres to strict guidelines to ensure integrity -known as scientific method -ensures observations free of bias -Scientific method: "Method of procedure that consists of observation, measurement, and experimentation, and the formulations, testing, and modification of hypotheses." Slide 7: - Scientific method: 1. Formulate question 2. Generate a hypothesis 3. Collect data by observing and experimenting: -Recall: science/technology must meet criteria of acceptance 4\. Interpret data -Sometimes adjust and re-perform experiments 5\. Draw conclusions - When a hypothesis is validated through experimentation, it becomes suitable as evidence (generally accepted in field, peer reviewed) Slide 8: Crime Scene Investigation - Crime scene: - Properly recognize, identify, collect, and preserve evidence at a crime scene - Attends the crime scene, in Canada we called them "Forensic Identification Officers." (members of police), forensic scientists don't work for police, but work with them - Forensic science: - Works in a forensic laboratory - Perform scientific analyses on evidence submitted by the crime scene investigator Slide 9: - Crime scene investigation is: - A methodological process -Follows set of principles and procedures that adhere to guidelines, but not rigid or fixed -Every crime scene is different -Crime scenes are unpredictable - A dynamic and thoughtful process -Requires an active approach -e.g. how pieces of evidence link to one another -Experience and observation are key -Every crime scene is so different, must be flexible, can't go near evidence though the guidelines may suggest to do so -Follow guidelines if you can (think to dairy queen explain about blizzards) - Grounded in the scientific method Slide 10: Crime Scene Investigation - Objectives of crime scene Investigation: - Recognize and identify forensic evidence - Collect and preserve evidence - Reconstruct the crime - Assist in the formation of a theory or theories about the crime -For ex. May ascertain the sequence of events leading to a crime, assist in uncovering a motive, etc. -Anything can be evidence -Every type of evidence will have specific transportation and packaging guidelines Slide 11: The CSI Effect: Overview - Unrealistic explanation of capabilities of forensics and crime scene investigation - Not new: a century ago, this was known as the "Sherlock Holmes Effect" - Result of inaccurate depictions in media -Result of inaccurate depictions in media: -Roles and responsibilities -Capabilities -Nature of evidence -Procedures and time frames -Two different people with different qualifications will collect evidence and analyze it -Every contact has a trace, doesn't mean it's useable -Fingerprints are dependent on sweat (if you wipe your hand, it may not show up) Slide 12: The CSI Effect: Analysis - Potential impact on real criminal justice system - CSI is unique because it presents a different model of police procedurals; other shows present forensics as a cog in the criminal justice wheel - 'Without a Trace': federal point of view - 'Law and Order': judicial processes - 'Cold Case': closure and eyewitnesses - 'CSI' places forensic science at the forefront - Focus on collection and analysis of forensic evidence Slide : The CSI Effect: Impact - General impact is on public perception - Impact on Court and legal system - Jurors - Prosecution - Defense -Higher rates of acquittal and conviction - Judge - Impact on criminal activity: - Does the CSI Effect serve to educate current or prospective criminals? Slide 13: -Be able to differentiate the two -Education and Awareness - How can we respond to this phenomenon? - In this course we will unpack the CSI effect, learning about how myths differ from reality -Question: -"Are there positive aspects of these media representations of forensic science and crime scene investigations or not?" ADVICE: -readings before LEC -write notes beforehand, read readings first, take notes after, summarize paragraph (1-2 bullets) \--ANY GOOD PAPER DELVES INTO BOTH SIDES OF THE ARGUMENT \- over reading week, watch "making a murderer" **LEC 2:** Slide 1: Roots of Criminal Investigation - Forensic science as a relatively new career field - Traced to approximately 1248: - China: -Postmortem examination may give information about cause of death -Forensic science draws from many fields (doctors, lawyers, etc.) - Interdisciplinary nature of forensic science and crime scene investigation - Pioneers in other fields relevant to development of crime scene investigation Slide 2: "Kin policing" in early clan life: - All clan members were responsible for determining sanctions to impose on violators - Absolute: - Serious offenses: banishment, death - Less serious offenses: corporal punishment, property transfer -Branding/mutilation to mark offender -"Among ancient Hebrews, law enforcement responsibility of kings, high priests, and elders: - Individuals appointed by society to apprehend and punish - Continued to Roman rule - Way of policing society continued to Roman rule Slide 3: - Ancient Babylon: - Codified laws into 'Law of Hammurabi' - Approximately 1700's B.C - One of the earliest and most complete written legal codes -Legal codes: -282 rules -Messengers assigned to carry out law - Foundation for establishment of a judicial system - Many harsh punishments for the guilty (e.g. removal of the tongue or hands) - Early example of "innocent until proven guilty" Slide 4: - 5^th^ century B.C., Romans adopted first written laws - Twelve tables (' -Rights and responsibilities of the Roman citizen -Legal procedures -Property ownership, building codes -Punishment for crimes - Police officials called Quaestorees Parricidi: - to track murderers - foundation for modern detective Slide 5: - From collapse of Roman Empire through early Middle Ages, formal law enforcement essentially non-existent as tools for social control - Individual offenses punished through: - Trial by ordeal (putting their hand into a pot of boiling water, if their hands burned, guilty, or not burned, not guilty but a witch, then burned) - Trial by combat - Court of the star chamber (derived it's authority from the king, used brutal methods to try suspects) -Authority from the king -Legalized methods or torture to force confessions from suspects Slide 6: -Question: What is the "legal age of reason of the offender?" -Age at which children capable of acting responsibly -Question: What aspects of today's criminal justice system stems from this idea? -Juvenile versus adult Court systems Slide 7: - 13^th^ century, emerging EU powers developed structured law enforcement systems - Classification of crimes - English defined the legal age of reason Slide 8: - Enforcement methods: - Hue-and-cry system: -Early English practice, pursuing criminals with vocal cries to alert neighbours (ex. sticking your head out of a window and yelling) - Watch and ward system (known as "night watch" today) -guarding city/village gates at nights -apprehend suspicious persons - Office of sheriff Slide 9: Policing - 1750: Henry Fielding established the Bow Street Runners in London, England - "Thief takers": -accepted cases only from those who could afford the fees -initially tasked for tackling robbery gangs - First professional police force -Wealthy people could typically afford policing - Practices developed still in use: -hiring informants -criminal raids Slide 10: Policing - 1810 French Surete (security): - First formal use of the detective in modern times - Founded by Eugene Francois Vidocq - Only criminal can fight crime - Believed in obtaining intimate criminal knowledge - Planted undercover investigators in prisons - Preventive role: - patrolling street - maintain public presence - investigate crime Slide 11: - North America saw benefit of **formal, uniformed** police presence - 1834: Toronto saw the first formal and uniformed police presence (municipal force) - 1838: Montreal - 1840: Quebec City - Canadian legal traditions overall can be traced earlier - Provincial police forces in rural Eastern Canada (1867) - 1873: Expansion into North and West -North-West Mounted Police -population density more crime with an increased population -forerunners for Canada's Royal Canadian Mounted Police (RCMP) -Toronto would be the first Canadian city police presence Slide 12: - Criminology: - Study of crime within society - Exploration of criminals and their treatment - Criminalistics: - Study of evidence to investigate crimes - Known today as 'forensic science' Slide 13: Philosophies in Criminology - Atavism: - Criminals born to commit crimes due to biological deviance - Biologically deviant, born a criminal, in their nature - **Cesare Lombroso (1835-1909):** -Psychiatrist -"Father of modern criminology" -He was an atavist - Positivism: - Criminals exist because crime is the product of social causes - **Alexandre Lacassagne (1843-1924):** -The way you were raised, the environment you were raised in -Professor of legal medicine -"Father of forensic science" Slide 14: Impact of Criminology on Criminalistics - How do these philosophies relate to criminalistics? - Influenced others to generate systems/methods -formed the basis for those used in investigations today (building blocks) - From forensic perspective, role of Lombroso and Lacassagne in history: - Influence first forensic scientists -Slide 15: - Alphonse Bertillon (1853-1914): - Lombroso (atavist): understand inherent morphology of criminals (criminology) - Bertillon: create identification system for recidivist offenders (repeated offender) (criminalists) - Systematic approach to criminal identification through 11 measurements of the body - Officially implemented in 1883 ('Bertillonage method'): - Widely accepted until 1920's -Bertillon assumed that the bones are all fully formed by the age of 20's -11 bodily measurements (ex. length of one's outstretched arms), kept on notecards, and kept at the police station, used to identify criminals - Bertillonage method: - Problematic: time + efficiency accuracy, subjectivity (the position of the arm changes length, if you know your ear will be measured, you can cut your ear off, twins) -began the foundation for the concept of the mugshot (only advantage of this approach) Slide 16: - **Edmond Locard** (1877-1966): - Another key player in the history of crime scene investigation - Also impacted by criminology and the philosophies therein - Positivism-Lacassagne was his predecessor -Locard's exchange -Lacassange encouraged Locard to study law alongside his medical work - Developed methodology for examining: - Cause of death - Associated physical evidence (anything not biological-like dust, dirt) Slide 17: - Late 1800's and early 1900's: contributions to forms of classification and identification - 1883: Alphonse Bertillon: -Method of criminal identification ('mugshot') - 1892: Sir Francis Galton: -Introduced fingerprinting method - 1898: Paul Jesrich: -Categorization of bullet striations (new and innovated at the time as guns were new as well) - 1901: Karl Landsteiner: -Blood grouping system (don't have DNA yet, but know that blood can be of different types) - Advances impacted by field and pioneers of criminology - Formed basis for criminalistics Slide 18: - Hans Gross (1847-1915) - Professor of criminal law - Recognized role of science on determining legal outcomes - Published the 'Handbook for Examining Magistrates as a System of Criminology' -Magistrates: -Need for legal professionals to understand scientific study of crime -unified science and law - Coined the term: - 'Criminalistics' - Gross is known as the father of criminal investigation Slide 20: Important Figures: - Sir Edward Richard Henry (1850-1931) - Metropolitan Police Force - 'Classification and Use of Fingerprints' - Henry: - formalized the ideas of Francis Galton into a classification system: - Henry classification system: - Fingerprint patterns to classify prints: -Loop -Whorl -Arch Slide 21: - Edmond Locard (1877-1966): - 1910: began using attic above law rooms to perform - Interested in: microscopic evidence (dust) - 1912: assisted police in solving the Marie Latelle case -Internationally renowned as first dedicated forensic laboratory - Locard's exchange: - every contact leaves a trace Slide 22: - Henry T.F Rhodes (1893-1969) - Use of the scientific method for crime scene investigation - "The process of crime scene investigation is scientific" - Published 'Clues and Crime' (1993) -Stated the objective of crime scene investigation was to determine: -How crime committed -Order of events -Scientific method foundational to these decisions Scientific method: 1. Formulate a question 2. Generate a hypothesis 3. Collect data by observing and experimenting 4. Interpret data 5. Draw conclusions Slide 23: - Paul Kirk (1902-1970) - Founder of American criminalistics - Published 'Crime Investigation; (1953) - Analyzed evidence in the Sam Sheppard case (1955) -Marilyn found murderer in bedroom in 1954 -Sam Sheppard fought with the perpetrator and was struck unconsciousness -Questioned about an affair (Susan Hayes), he was, the woman confirmed they did -Charged; wrongful conviction and overturned -Sam was charged with 2^nd^ degree murder -biased judge at the time -didn't investigate anyone else, wrongful conviction -jurors were influenced by media, not evidence, popular perception of him at the time - Physical evidence always present at crime scenes - only compromised through human error - Illustrated importance of recognizing evidence Slide 24: - Sir Alec Jeffreys (1950-present) - British geneticist - 1980's: individual identification can be made based on DNA -concept of genetic fingerprinting (different than DNA typing) -developed techniques for profile analysis of DNA - Paved way for current techniques of DNA analysis Slide 25: Development of Forensic Labs in Canada - Recall Locard established first dedicated forensic laboratory in early 1900's in France - In Canada: - Montreal: Laboratoire de Sciences Judiciaires et de Medicine Legale (1914) -Dr. Wilfrid Derome -Following the Locard model -First established in Canada, third established in the world - Toronto: Laboratory of the Attorney General in Ontario (1932) - Renamed Centre of Forensic Sciences in 1966 -Central lab in Toronto -Regional lab in Sault Ste. Marie -CFS (centre of forensic scientists) Slide 26: The Crime Lab - Scientists are civilians (specialists or technologists) - Analyze evidence - Testify in court - Full-service laboratory includes: - Toxicology - Biology - Firearms and tool marks examinations - Questioned documents - Photo analysis - Electronics - Chemistry Slide 27: - Operate under established protocols and guidelines - Ensure integrity of scientific analyses - Laboratories may become accredited (legally recognized) - American Society of Crime Laboratory Directors - Uphold quality assurance and quality control - Requires extensive reviews and examinations -Credentials of personnel -Administrative practices -Use of evidence controls -Type of examination methods Lab 3A: Slide 1: Defining a Crime - "An act punishable by law" - Deemed by a statue or common law to be public wrong: - Punishable by criminal proceedings - All crimes are different but may have a pattern: - Modus operandi - Pattern of criminal behaviour - Criminal acts or behaviour may be proved by evidence Slide 2: - Crime scenes yield physical evidence - Require control, maintenance, and documentation - Only things consistent about crime scenes are: - \(i) Locard's Exchange Principle: -Every contact leaves a trace - \(ii) Their consistency: -Every crime scene is different -For example: one room in a house versus a large property or farm -"Any place in which a crime occurred, or in which evidence relating to a possible crime has been located." **Slide 3: Defining a Crime Scene** - Crime scenes are diverse - Every crime scene is different - Many ways to classify crime scenes: - Primary versus secondary - Macroscopic versus microscopic - Based on type of crime - Based on crime scene condition - Based on crime scene location Slide 4: Primary versus Secondary Crime Scene - Designation of sequence of events: - Does not indicate priority or importance - Primary crime scene: - Site of original criminal activity - May yield more useable evidence (not always!) - Secondary crime scene: - Also known as subsequent crime scene - May be the first scene investigators encounter - Use evidence to locate primary crime scene - May also be tertiary, and so forth Reminder: -Recall: relates to sequences of events, not importance of evidence -Case example: woman is sexually assaulted, middle of the night bald, no condom, a struggle ensues, woman is strangled with a tie, placed in vehicle, transported into woods, buried with tie Slide 5: Macroscopic versus Microscopic - Based on size of the crime scene - Macroscopic crime scene: - Possibly composed of many crime scenes: - For ex. victim stabbed in park,: The park, the body, the wound, and the ground around the body - Microscopic crime scene: - focused on specific types of physical evidence found in the macroscopic crime scene - For ex. trace evidence on the body or impression marks on the ground beside the body Slide 6: - Based on the type of crime committed: - Homicide - Suicide - Arson - Robbery - Sexual Assault - Not as descriptive as other classifications -Crime type may change during investigation Slide 7: Based on Crime Scene Condition - Roots in criminal behaviour and profiling - Widely used in classifications of violent or recidivist (repeating) offenders - Organized crime scene: - Indicates premeditation, planning, and control - Scene more orderly - Offender more likely to purposefully conceal the body or remove evidence from the crime scene - More likely to take weapon with them - Disorganized crime scene: - Reflects sense of disorder, little (if any) premeditation - Ex. hit and run - Scene is often in disarray, evidence more likely to be found, body often in open view - Disproportionate number of scenes are disorganized - Used as an adjective, not a nail Slide 8: Based on Crime Scene Condition - Based on the physical location of the crime scene: - Indoor - Outdoor - Vehicular - Aquatic - Also not as descriptive as other classifications Slide 9: Are all crime scenes different? - Crime scene can take many forms - Must avoid making assumptions: - Cannot assume "known" is all that exists -Primary versus secondary crime scenes -Are all scenes crime scenes? Cannot assume all scenes are crime scenes. Slide 10: Managing Crime Scenes - Approach every scene as if it is a crime scene - Ensuring integrity of evidence key to whether evidence will be admitted in Court - Strict management - Crime scene management includes: - The initial response - Securing and preserving the crime scene - Scene assessment and documentation - Searching the scene - Releasing the scene Slide 11: - Early step in managing the scene: establishing the crime scene area: - Inner perimeter: -Core area where criminal act took place -evidence most likely to be compromised - Outer perimeter: -Larger perimeter surrounding inner perimeter -Crime scene tape - Important to manage scene to allow for: - Full investigation - Proper documentation and collections of physical evidence - Admissibility in Court Lecture 3B: Slide 1: Roles and Responsibilities - Popular media represents crime scene investigators as amalgams of many different roles - Each is distinct and requires focused training and education - Crime scene investigator only responsible for attending the scene, collecting evidence - Result of popular media representations: - Glamourizing - Public misinformation - Lack of understanding of complexities of the multidisciplinary nature of investigation Slide 2: - Incident reported and first responders dispatched (three-tiered response) - Responding first officer performs scene assessment, decides immediate action, secures scene: - Recall the inner and vs. outer perimeter - If known or suspected death, becomes death scene: - The coroner or medical examiner called-one enters without permission - A ranking officer arrives at crime scene - Responsible for managing the investigation - Meets with those on scene for preliminary briefing - Crime scene investigator consults with lead/ranking officer in charge upon arrival Slide 3: Who is Who? 1. Uniformed patrol officers: - Constable - Responds to emergency calls for service - Assume control until relieved by police supervisor or crime scene investigator 2. Uniformed police supervisor: - Sergeant - Supervision of patrol officers (constables) - Assumes control of crime scene until relieved by criminal investigator or crime scene investigator 3. Detective: - Criminal investigator - Police officer (any rank) for crime investigation - Conduct and manage investigation, prepare case for court, assist prosecutor - May be multiple for one case-usually lead Slide 4: Crime Scene Investigators in Canada - Highly trained, sworn police officers - Called "Identification Officers" - To enter Identification Unit must: - Become sworn police officer - Complete basic training - Work as general duty, uniformed officer - Work as a Scene of Crime Officer (SOCO) - Application to become Identification Officer - Spend time in the Central Investigations Bureau - Intensive course work Slide 5: - Depending on severity of crime and complexity of scene, 1-2 identification officer's - Death investigations: - 2 identification officer's:\ -Lead forensic investigator: - Scene management, prioritizing of examination, liase with outside investigate personal -Less experienced forensic investigator Slide 6: \- Civilians may become involved in crime scene investigation - Civilian: someone who has not completed formal police training/is not sworn - Work with police in uniform - No use-of-force abilities -Forensic Identification Assistants\ Assist Ident Officer in processing evidence Toronto: \*crime scene support tech\* -Generally requires background in forensic science Slide 7: Important Scene of Crime Officers (SOCO) and civilian Crime Scene Support Techs merely assist the Identification Unit Process evidence, generally do not assist with longer serious scores e.g. no shooting reconstructions Regardless of role, duty is to the scene - Do not work in the laboratory Slide 8: Forensic Scientists in Canada - Evidence is submitted to the crime lab by Crime Scene Investigator - Enters Case Receipt Unit - Exhibits tagged with computerized monitoring system: - Allows personnel to see: - Where evidence is - Who has it - How far the analysis has progressed Slide 9: - Exhibits go to the Evidence Recovery Unit ERU technologists locate and collect all forensically important material - Submits to appropriate unit for analysis - In Ontario, this is done by CRO personnel - Forensic scientists: - Civilian - Employed by crime or forensic laboratories Slide 10: - Forensic biology one of largest sections - Forensic biologist: - Analyze biological materials - Area of employment depends on expertise - Human or non-human - DNA analysis - Minimum honours degree: - Biology, biochemistry, molecular biology - Most have graduate degrees - Extensive training in lab: Do not become an analyst or specialist right away Slide 11: - Forensic toxicologist: Determine presence and amount of toxins in body fluids and paraphernalia Toxins: drugs, alcohol, poisons - Determine physiological effects: - What was the original dose? Was it enough to kill or impair the individual? - Minimum honours B.Sc. (most have graduate degrees) Biochemistry, pharmacology, physiology, or chemistry - Extensive training before solo work Slide 12: - Different labs have different names for this unit (e.g., 'Trace Evidence Unit') - Forensic chemist: - Also known as 'trace evidence specialist' - Analyze non-biological trace evidence and substances - E.g. paint, clothing, fibres, gasoline - What substance is and its chem or element amount % - Minimum honours B.Sc. : Chemistry background (most = graduate degree) Extensive training before solo work Slide 13: - Firearm examination is not ballistics - Tool-mark and firearm specialist - Analysis of tool mark, tool, firearm, or ammunition - Physical matching of tool to suspect mark - Firearm specialist may also: - Restore serial numbers - Assess mechanical condition, safety, legality - Maintain Canadian Integrated Ballistics Identification Network (CIBIN) - Minimum honours B.Sc. (engineering or physics) - Extensive training before solo work Slide 14: - Questioned document: contains letters, numbers, or symbols that could express meaning; authorship in doubt - Questioned document examiner: - Analyze or compare handwriting - Examine document alterations Minimum honours B.Sc. (chemistry) -number if word blindness and dexterity tests Slide 15: Other Team Members Variable depending on complexities and requirements of each investigation: - Dive/underwater search teams, aerial search teams - Medical examiner/coroner - Hazmat response team - Forensic psychiatrist - Forensic anthropologist - Forensic odontologist: petition of skeletonized or decomposed remains, collection/preservation or bitemark evidence - Forensic entomologist: insects associated with human body to estimate elapsed time since death - Forensic botanist: Plants or pollens to imsuspect or items - Generally outlined by professional organizations (e.g., AAFS) - Synopsized as (Gardner and Bevel, 2009): - Be conservative - Communicate accurately, precisely, without ambiguity - Use proper tests, procedures, methodologies (remain current) - Does not meet requirements of true science - Unproven or questionable research - Research driven by personal gain - Current "scientific" methods under fire: - Fire investigations - Lead bullet analysis - Hair analysis - Bitemark analysis - Ethical responsibility to utilize proper, currently accepted tests, procedures, methods - Error can be made at any point - May affect validity of established conclusion - May lead to flawed understanding of events - Wrongful convictions - Types of error: - Ethics violation - Honest error - Lack of training - Pressure - Administrative errors - Complacency Slide 20: Cognitive Bias - Bias may also be a factor in error - Broad term that includes a variety of processes that may lead to inaccurate judgements - May affect memory, reasoning, decision making - Types of bias: - Confirmation bias: - Context bias: Slide 21: Managing the Risks of Bias: - Humans are inherently subject to influences that can negatively affect ability to reliably and effectively evaluate and act - May result in: -Miscarriages of justice -Loss of public confidence - May not be able to eliminate but can manage - Training and proficiency testing - Limit daily pressures - Work Blindly - Seek to disprove **Week 4-4A LEC**: Slide 1: Arriving on Scene: Priorities of First Responders - Many jurisdictions rely on 3-tiered response: - Police department - Emergency medical services (EMS) - Fire department - Safety of first responders and those at/near scene is the priority - Responding police officer identifies and initiates the appropriate response - Next priority: preservation of life - Even at expense of evidence/scene preservation Slide 2: Scene Alteration: - When possible, first responders should avoid altering the crime scene - Initial response must be effective, efficient, methodological -Preservation of life is paramount - Scene alteration not a problem if reasonable explanation exists as jurisdiction for such Slide 3: - Examples of reasonable explanations or justifications for an altered crime scene: - Damage caused to gain entry - Damage from suspect apprehension - Item relocation from medical assistance - Environmental effects - Time lapse prior to scene discovery - Police must maintain documentation of what happened, how scene was altered - Provide to detective or investigators Slide 4: Role of responding police officer: - Responding police officer often first to arrive - Duties of a responding officer: - Safety of first responders - Preservation of life; safety for others on scene - Scene security and preservation - Thorough documentation - Transference of responsibility - Same despite - Do not rush into a scene; observe and assess - Responsibility to try to preserve physical evidence subject to alteration by lifesaving actions Slide 5: Safety at the Crime Scene - From immediate threats to the safety of first responders or others at the scene - Safety of responders of paramount importance - First thing responding police officer must do is render the scene safe - Suspect may be on scene - If flies, take reasonable measure to protect scene while attempting apprehension - When site is deemed safe, lifesaving measures may be implemented by responding personnel Slide 6: Scene Security and Preservation - When scene deemed safe, assess situation - Proceed with extreme caution when entering crime scene - Be aware of where evidence may be found - Observe all details - Important to document everything - Securing the crime scene mitigates evidence removal or alteration, and/or contamination - Locard's Exchange Principal -Demonstrates the importance of scene security and maintaining the integrity of a crime scene Slide 7: Scene Security and Preservation - Scene security maintained through: - Physical presence: -Police guarding the crime scene - Police line tape - Locks and barriers -Locking a door (indoor scene) - Barricades with vehicles, boards, etc. - Method depends on scope and location of crime scene - Death investigation: tent to conceal remains Slide 8: Determining the Scope of the Scene - Recall: typical crime scene consists of: - Inner perimeter -Core area where criminal act occurred - Outer perimeter -Including probable entry and exit routes -Police tape - Perimeter prevents damage to potential evidence - Rule of thumb: designate large perimeter and reduce if prudent to do so -can be reduced without sacrificing integrity of crime scene Slide 9: Path of Contamination - Arrival to scene is chaotic - Assess scene boundaries and instruct emergency personnel of best route of entry - Responding officer should establish a 'Path of Contamination' - always used to access crime scene - ideally, path least likely travelled by the suspect and the victim - avoid potential paths of a perpetrator - ruining evidence Slide 10: Maintaining a Security Log - Scene security designated - Prevent entry into the crime scene by unauthorized persons -Remain on scene until processed - Must also keep record of all those that enter and exit the crime scene - Crime scene access log Slide 11: - Crime scene access log important - Ensures: - Crime scene and evidence correctly interpreted -Possible contamination and cross-contamination documented - Especially important in cases where the crime scene record and evidence analyzed some considerable amount of time after processed Slide 12: Documentation for Responding Police Officers - When entering crime scene, observe and take written notes as soon as possible - Initially, scene chaotic -Documentation may not be a priority -May be done retrospectively (as soon as possible) Slide 13: - Important to document: - All information surrounding dispatch and arrival at the crime scene - All info surrounding - For example: - Important that all actions are documented, even negative ones -Recall: investigate ethics; must be honest and transparent -Mistakes or honest errors must be disclosed -May turn out to be of little significance with respect to scene integrity, but failure to document may result in the officer's personal integrity being questioned Slide 14: - Important to document: - All information surrounding what (if any) lifesaving measures were administered - If injured must be removed from the crime scene, should document things such as: -Location of individual within the crime scene -Position of the injured person's body -Condition of injured person's clothing Slide 15: - Also important to document: - Any information from witness -Information given at the scene may change as time goes on or be misinterpreted/misperceived -Take notes; not a full interrogation - Any information from suspects - Scene conditions: - For example: - Date and time indicators: - For ex: mail that was dated from the week prior but had not yet been picked up? Slide 16: Transference of Responsibility - While waiting to transfer responsibility, responding police officer may: - Write down names of those who interacted with the crime scene - Ensure documentation requirements fulfilled - Establish basic facts -Factual account of what happened; not full interrogation - Keep suspects and witnesses separated - Instruct witnesses not to discuss event(s) - Protect evidence - Expand protective measures if required Slide 17: Arrival of the CSI - Usually, all threats to safety mitigated when crime scene investigator arrives - Personal safety of utmost importance - Must also mitigate risk of contact with potentially infectious materials - Myth related to the CSI effect: - What crime scene investigators wear when coming onto a crime scene - Often seen in glamorous clothing Slide 18: Contamination - Contamination may occur: - Between items of evidence - From crime scene investigators or other personnel not wearing proper attire -Inadvertently depositing their own DNA at the crime scene or at an item of evidence -Cross-contamination - Cross-contamination may undermine the integrity of forensic evidence Slide 19: Personal Protective Equipment: - Never enter the crime scene without personal protective equipment (PPE) - PPE may include: - Disposable Tyvek suits -With hoods or other hair cover - Disposable shoe covers - Mask or other respiratory protection -Cover the mouth and the nose - Goggles or eye protection -Face shield if droplets of fluid present -Never use face shield alone Slide 20: Personal Protective Equipment - PPE may also include: - Disposable gloves -Nitrile gloves -"Double-glove technique" -Worn when handling any evidence, potential evidence, or biological materials -Cut-resistant where applicable - In some cases: hard hart, high visibility outwear, firefighter bunker gear, specialized footwear, etc. - Never eating drinking, eating, or smoking at the crime scene -Protect evidence (e.g. divert water) -Must report everything to detective -report relevant details to crime scene investigators Arrival of the CSI: -Myth: -What crime scene investigators wear when coming onto a crime scene -often seen in glamorous clothing Contamination: -Inadvertently: -e.g. a stray hair, a sneeze -cross contamination: Locard's Exchange Principle -crime scene (wear steel toed boots) -aquatic scene , dive gear **Week 4-LEC 4B:** Slide 1: Crime Scene Survey: Initial Walkthrough and Preliminary Assessment - CSI one of the first *specialists* to attend scene - Contacted by criminal investigator or senior ranking officer (major crime) - Remember they aren't always required - Preliminary assessment performed - Assessment as an ongoing process - Initial walk through (without documenting anything, photographing anything) - Major crimes= criminal investigator and CSI -CSI decides who accompanies them during that initial walk through Slide 2: - "Look, but don't touch" - Develop a plan or approach - Initial walkthrough as an opportunity to: - Determine nature and extent of the scene - CSI may reconsider the established perimeter - Are all appropriate areas under control? - Develop theory of the crime - Create a rough sketch of evidence location -Develop team approach -Determine appropriate search technique Slide 3: Legal Aspects: Search and Survey in Canada 1\. Search: - "Something that infringes one's reasonable expectation of privacy" 2\. Seizure: - "The taking of a substance of thing belonging to, or in the care and control of, a person by a public authority" Slide 4: - Reasonable searches and seizures accepted as valid social safety mechanism - Balanced with individuals right to privacy - "Everyone has the right to be secure against unreasonable search or seizure" (S.8, Charter) - Requires unjustified searches do not occur -Accomplish by judicial pre-authorization -Search warrant: authorizes police or other official to enter/search the premises Slide 5: - Search warrant: - Provides judicial review re: reasonable ground for infringement on privacy - Places restrictions on search: how, when, where - No warrant= search presumed unreasonable - Prosecution must prove search not unreasonable -Evidence may be inadmissible Slide 6: - Exceptions to general rule of judicial pre-authorization \(i) Incident to arrest and investigate detention - May search person and immediate vicinity to arrest and seize, if search conducted in reasonable manner \(ii) Consent and abandonment - Person has a reasonable expectation of privacy in relation to the entity to be searched and gives consent **or** Property has been abandoned (location and intent) - Gives consent (e.g. person charged with homicide gives permission to search) Slide 7: - Exceptions to general rule of judicial pre-authorization - When conducting lawful search re: one crime and evidence of another crime is in plain view, it may be seized \(iv) Exigent circumstances - If Court finds circumstances existed that required immediate action to ensure safety or secure and preserve evidence where not feasible to first obtain judicial authorization - Examples of exigent circumstances: -2010, accused person called Toronto humane society to help her carry cat after it gave birth, saw mutilated kittens and alove kittens. Accused become very agitated, arrested for intoxication -2006, the accused was a resident in a men's hostile, police had seized his bedding, believed to have blood on it, concerned if they went through the process of search and seize, the evidence would get alerted, or even washed Slide 8: Methods of Searching - Crime scene searches are intrusive - Primary scene context (before search) must be well-documented - Search must be systematic and methodical - Ensure all evidence and details noted - **Priority should be evidence at risk of deterioration** - Most used search methods: - Strip, grid, link, zone, wheel, spiral - Dictated by environment, scope of scene, available manpower and resources - Under what context would these search strategies apply? Slide 9: - Search team must be aware of: - What method will be used - How to conduct the search - How to manage evidence found -Mark items without touching or altering -Alert the search leader: raise hand, use code word Slide 10: Searching: Strip Method - Also known as the 'line method' - Horizontal strips - Search in strips approximately 2-4 ft wide - Multiple searchers may form line where search strips overlap -Supervised by search leader -Search left to right -Move at same pace - Best in large or outdoor scenes - Popular in forensic anthropology Slide 11: Grid Method - Also known as 'double strip method' or 'double line method' - Line search one direction, change to 90-degree angle, search again - 2 searchers, lines of searchers - Pro: scene to be searched twice - Less likely to miss small or hard to recognize evidence - Con: time-consuming Slide 12: Link Method - Most common search method - Based on linkage theory - One thing influences/determines the process or outcome of another - Not geometric - Based on findings, observations, logic - Probability that based on the crime, evidence likely to be found in a particular location - Works for any scene type (outside or inside) - Problem: starting where all the evidence is, normally we work from outside to inside of scene Slide 13: Zone Method - Best on scenes with defined zones - For example, houses with rooms - Allows for certain zones to be prioritized - May utilize other search methods within each zone - Method works well with search warrants - Allows certain areas to be searched where other areas not specified or allowed Slide 14: Wheel Method - Also known as the "ray" method or the "pie" method - Search from a critical point moving outward, in straight lines - For example, from the deceased - Not common, limited applications - Most often used in circular crime scenes - Not good for large crime scenes Slide 15: Spiral Method (starting inwards) - Inward or outwards spirals - Inward: start at outer boundary and circle towards critical point - Outward: start at critical point and circle outward - Searcher trace regular pattern with fixed diameter - Works best on crime scenes without physical barriers - Most common in outdoor scenes - You do a reseverse spiral search, which solves that issue - Generally one person does this search Slide 16: Vehicle Searches - Vehicle searches are unique in that: - Search in a restricted space - Processing of the interior and exterior - Presence of an undercarriage - Must also process the location where the vehicle was found - Process similar in most jurisdictions - Tow vehicle for secure processing - Conduct preliminary search for evidence that could be damaged in transport Slide 17: Vehicle Search Process - Begin with exterior of the vehicle - Search for: -Damage -Cloth imprints or road grime on the finish -Trace evidence -Fingerprints -Doorhandles -Outside mirrors -Windows -Trunk lock area - Careful attention to hood and grill areas if suspected of being involved in an accident Slide 18: - Commence search of interior - Generally divided into five segments, always in same progression -Begin by searching segments for fingerprints -Re-search segments to search for evidence - Next, search trunk and hood of vehicle - Undercarriage searched - Generally reserved for instances where vehicle is suspected of having been in an accident **Online Lecture, Week 5**: Slide 1: Documenting the crime scene - Purpose of crime scene investigation: - Collect information to determine what occurred - Preserve crime scene context and evidence - Documentation for crime scene investigations - Begins even before arrival on scene - Once initial walkthrough is completed, must document the scene in detail - Documentation as a permanent record: - Preserve crime scene context and evidence - Documentation requires crime scene\ investigators be organized and systematic\ Time consuming - Four tasks of documentation: - Note taking - Videography - Photography - Sketching Usually this order (every scene is unique)\ **All should occur before evidence collection** Slide 3: Taking notes at the crime scene - Done as events unfold, detail step-by-step\ actions\ Not retrospectively -memory loss may affect accuracy and quality Note taking is important because:\ -Provides permanent record of scene -Criminal investigators may rely on case notes in the future, particularly for drawn out investigations\ Seemingly insignificant information may turn\ out to be significant Slide 4: -Crime scene investigator should document: - Notification and arrival information (at "x" time I was dispatched? By who's authority? How did you arrive?) - Information surrounding initial walkthrough (did the CSI go the walkthrough on their own, or did they have someone accompany them?-imagine if prints of another officer was there, and the CSI investigated the scene on their own, then that officer could be a suspect) - Description of the crime scene and scene conditions (can record the weather, temperature, if it rained the previous night, is this dirt dry or damp? Is it snowing?) - Description of the victim (if applicable) - Description of crime scene search and all evidence (documentation continues from start to end) Slide 5: Taking notes at the crime scene - General order but every crime scene is\ different - Meticulous note taking is the key to\ competent crime scene investigation\ Importance of transparency\ Notes should never be erased or edited -If mistake made or something must be amended (key is transparency!(no erasers or whiteout): -cross out with a single line, and intimal beside it -never edit notes on iPad either Slide 6: \(i) Notification Information: - Date/time notified - Method of notification (by who?) - Information received when notified -For example: -Type of crime -Location of crime scene - Any other information relayed (what have the other officers on the scene have done already? Who the coroner or medical examiner is? Who will be your point of contact before you arrive?) - Means of transportation (did you arrive by car? From your parking spot, need an ATV or hike up to the scene?) - Date/time of arrival at the crime scene - Personnel present at the crime scene: -Names and affiliations -Names of witnesses - Any information provided upon arrival (e.g. from the initial responding officer-ex. you may be called to a scene at 11pm but can only reach there the next morning. What has happened in between?) Slide 7: \(iii) Initial Walkthrough Information: - Date/time it began - Who performed? - Who else was in attendance? - Identification of evidence during (ex. you see a gun on the ground, take note of that as well as the position) - Date/time it ended - Results of the initial walkthrough -For example: Designated particular assignments to team members \(iv) Scene Description: - Description of crime scene location -Surrounding houses and streets (residential or rural area? Did it happen in a farm? Or in a bedroom?) - Description of the crime scene -Indoor: describe interior and exterior -Outdoor: describe terrain, flora, fauna - Condition of crime scene -Messy? Clean? Evidence of recent activity? (ex. food, old and moulded? Or fresh? - Weather at the crime scene (normally initial documentation, but it can change throughout the day) Slide 8: \(v) Victim description: - What information is collected on whether victim is alive or deceased - Victim's physical description (rough estimate of height, colour of hair, eyes) - Relevant demographic information (e.g. age, biological sex, colour of skin) - Description of any visible wounds - Presence or absence of identification - If deceased: position of body, information on lividity, evidence in relation to the body (is the gun in the bathroom and the deceased person is on the balcony? Or are they on the floor and the gun is beside them?) - Recall: if victim is deceased, body cannot be touched/disturbed without explicit instructions from the coroner (may not be able turn body over, or try to find ID) - Be aware of the limitations of your knowledge - Only document what you see and what you know as a fact Slide 9: \(vi) Detailed evidence handling results: - Physical description of evidence exhibit - Location of evidence exhibit - Position of evidence exhibit - Evidence collection details - Who? - Name and affiliation - When? - Date and time - Results of search for fingerprints, DNA, trace Slide 10: - Crime scene investigators should use best judgement, training, and experience - Every action should be documented: -In the order it is performed -In detail - Make a conscious effort to present negative or unexpected conditions as well (if the back door is not open but closed, deceased body and no blood on the ground) - For example: - -Absence of bloodstains where such is expected - One light that is on when all others are off Slide 11: Video recording of the crime scene - Routine in major crime, discretionary for other crimes (mostly first responders like police officers use this, not CSI's) - Advantage over still photography: graphical depiction that shows spatial relationships within the crime scene - "Virtual initial walkthrough" - Done in *addition* to other documentation efforts - During or immediately following the initial walkthrough Slide 12: - Guidelines for videography: - No equipment or personnel (no tripods, people, garbage) - Must remain objective (don't record audio, narrating could introduce subjective bias to the viewer, allows for viewer to draw their own conclusions) - May use placard at beginning of video to provide relevant information (sort of like director's "cut!" piece) - Videographer's name - -Date/time of video recording - Location - Case number Slide 13: - Effective videography of a crime scene includes all aspects of the initial walkthrough: - Begins with crime scene surroundings - Include roads to and from the crime scene - General view of the crime scene - Enter the crime scene - Move through the crime scene in a systematic way - Showcase orientation of items of evidence in relation to the overall scene (wide angle-perspective) (use linkage theory to determine what our next steps are) - Pan the area and then zoom in on evidence exhibits -May utilize a scale - Leave the crime scene (tells us how long the initial walkthrough was) - Video recording of spectators or other individuals surrounding the crime scene (if relevant, as some criminals return to the crime scene) Slide 14: - Recall: no documentation of a crime scene should be deleted or altered in any way - Documentation as evidence - Best practice: - Review the video recording on the crime scene in real-time - Re-shoot if necessary (no documentation should be deleted) Slide 15: Photographing the Crime Scene - Photographing the crime scene serves several purposes - Refreshing memory -Crime scene investigators -Witnesses - Demonstrate spatial relationships between items of evidence - Convey image of the crime scene and circumstance of the crime to the trier of fact (being either the judge of jury) - Must be admissible - Must be able to testify photo is an accurate depiction of area shown (and if it's not accurate, it may not be admissible in the court of law) Slide 16: - To accurately depict the area shown, photograph(s) must: - Represent subject matter in: -Colour -Scale -Form - Be in focus - Show relationships between objects - All digital files should be retained - Ensured through use of a photo log (number the photos, similar to a security log) Slide 17: Photo log - Photo log: proof of a documentation photo being taken at a crime scene - Typically includes: - Date (date that each photo was taken) - Case number - Photographer's name (different names for each photo, who did exactly what?) - Information on equipment used to take the photo (e.g. camera type, lens used) - Information specific to each photo: -Photo number -Time photograph was taken -Type of photo (overall, mid-range, close-up) -Description of what the photo shows -Listing of each photograph (e.g. shutter speed, distance from camera to object)-done for every photo Slide 18: Equipment used for Photographing the Crime Scene - Still photography used to be the norm - 35 mm film Single Lens Reflex (SLR) - Today, majority of agencies use digital photography (DSLR) - Greater flexibility - Ability for images to be incorporated into digital reports - DSLR cameras have varying resolution capabilities - Higher megapixel capability ideal - Allows for quality photo enlargements Slide 19: - Flash system - External flash often better than those built into the DLSR camera - Benefits of external flash -Control of flash/lighting Direct flash to certain area -Bounce flash off lighter surface -Enhance details of patterned evidence -Illuminate areas in shadows Slide 20: - Camera lens: tool to bring light to a fixed focal point - Lenses for DSLR camera are interchangeable (have different lenses to capture different things) - Benefit of choosing which is most appropriate - Normal lens approximately 50 mm (typically what human eyes perceive) - Duplicates what normal eye perceives - Crime scene investigators should generally choose macro lens - May take close-up photos and remain in focus Slide 21: Guidelines for Photographing the Crime Scene - Crime scene photography is systematic and organized - 'General' to 'specific': -Overall -Mid-range -Close-up - This guideline allows for: - Orientation of crime scene as a whole - Orientation of evidence within the scene - Provides quality photographs for examination Slide 22: Overall Photos: - Taken upon arrival at crime scene (usually photos taken first, then video captured of the scene afterwards) - Includes locator images - Demonstrate location of the crime scene - Serves to capture condition of crime scene before alteration occurs - Important to have overlapping coverage to show the entire expanse of the crime scene - Depict overall scene context Slide 23: - Exterior - Document: -Surroundings of the crime scene (other streets, or other homes) - May utilize aerial photographs: -Particularly useful for major crimes -May depict: -Location of indoor scene relative to larger area -Demonstrate the perimeter of large, outdoor crime scene (think of rural property, having to find a body in the middle of a field) - Interior - Document: -Actual crime scene location - Taken from all four cardinal directions (NESW) -Each room corner for indoor crime scene - All photos from those 4 directions should overlap - Should include doors leading into or from the structure -Provides link to exterior photos Slide 24: Mid-Range Photos - Also known as 'intermediate' or 'evidence-establishing' photos - Purpose - Show where evidence is in the crime scene - Transition viewer from overall to close-up photos - Take a mid-range photo, one with and without evidence marker Slide 25: Close-Up Photos: - Purpose: - Shows details of specific items of evidence or details of scene context -For example: -Details of tire tread mark -Layering of bed linen - Two types taken: - Photograph of evidence exhibit as it is found - Photograph of evidence exhibit with an evidence marker and a scale included -Important that plane of camera parallel to plane of object being photographed (take photo from directly above to avoid distortion) Slide 26: How Many Photos Are Required? - Recall: every crime scene is different - Any number so long as they serve a purpose - General rule: better to overshoot - When in doubt, take the photo - Every photo must be documented in the photo log -Never delete Slide 27: Sketching the Crime Scene - Permanent record of size and distance relationships of all the crime scene and associated evidence, using units of measurement - Routine in major crime, discretionary for other crimes (not done in every crime scene, only major) - Two types of sketches: - Rough sketch: -Often done during the initial walkthrough -Measurements added to this sketch after photography performed - Final (finished) sketch -Prepared for presentation in Court -Prepared based on the rough sketch Slide 28: - Every crime scene sketch should have: - Title or caption (which may include the case number) - Legend - Compass designation (indicator arrow, usually pointing north) - Documentation block: -Case number -Offence type -Victim name(s) (if applicable) -Date/time sketch done -Name and affiliation of sketcher -Scale (mapping scale, or can say "not drawn to scale") Slide 29: Types of Sketches - Crime scene investigator decides which type of sketch to prepare: - Floor plan - Elevation plan - Site plan - Cross-sectional plan - Each may have a rough version and a final (finished) version - Use depends on the scene location Slide 30: Floor Plans - Two-dimensional sketch - Provides bird's eye view of a room or series of rooms - Utilized for indoor crime scenes (makes sense because indoors have floors, so floor plans= indoor scenes) - Benefit: - Simple and easy -All items of interest are in one plane Slide 31: Elevation Plans - Two-dimensional sketch - Used when the vertical plane is of interest (think of a crime scene on a staircase, blood droplets rising up in elevation) - Utilized for indoor or outdoor crime scenes - Benefit: - Simple and easy -All items of interest are in one place Slide 32: Site Plan - Two-dimensional sketch - Bird's eye view (similar to floor plans except it focuses on outdoors) - Utilized for outdoor crime scenes - Benefit: - Simple and easy to interpret - May illustrate: - Property lines - Roads - Topography - May be obtained from other sources (CSI may not need to sketch it, just obtain it) Slide 33: Cross-Sectional Plan - Also known as "exploded view" or "cross-projection" sketch - Two-dimensional sketch - Combination of floor plan and elevation sketch - Utilized for indoor or outdoor crime scenes - Useful for forensic anthropology -For example: (aiming to document) Clandestine graves Slide 34: Measurements - All sketches contain measurements - Sketching the crime scene often done last because taking measurements is somewhat intrusive - Use caution - Four methods of measurement used: - Triangulation - Baseline - Polar coordinates - Perspective grid (photogrammetry) Slide 35: Triangulation - Measuring the distance from two fixed points to the location of evidence - Fixed point: unmovable item - Requires multiple people - Best for outdoor scenes or tricky contexts - Record: - Distance from each point to where tapes overlap over the evidence exhibit (where the tapes make the 3^rd^ point of the triangle) - Cardinal direction of each measurement ("Am I measuring 10 metres to the North or 10 metres to the South?") - Use multiple points if evidence large (ex. mapping out each end of a 5-foot-long shotgun) - Provides more accurate representation Slide 36: Baseline Measurements - Measuring the distance of an object from a baseline at a right angle (ex. measuring the bottom of one wall, and the next wall to create a right angle) - Indoor scene: baseline as a wall - Outdoor scene: baseline created from fixed point - Requires multiple people - Indoor or outdoor crime scenes - Record: - Distance from baseline to evidence exhibit - Cardinal direction of each measurement - Multiple points if evidence large Slide 37: Polar Coordinates - Also known as "map and compass" - Most simple, least accurate - Crime scene investigator stands at a fixed point, sights to evidence exhibit - Requires two people - Best over large distances - Record: - Distance from investigator to evidence exhibit - Cardinal direction of each measurement Slide 38: Photogrammetry - "Perspective grid method" - Places an object of known measurements into a photograph - Multiple, overlapping photos from multiple angles - Include standard measuring tool - Best done using specialized software - Measurement calculations based on known dimensions and camera's angle of view -Overlapping photos limit distortion Slide 39: Chain of Custody - Purpose: prove integrity of evidence submitted to Court - May otherwise be deemed inadmissible - Chain must show: - Details of evidence collection -Who collected this evidence? When? - Show subsequent contact with the evidence (Who had it? Who took it to the crime scene lab?) -At what time -Under what circumstance -Changes made to evidence - Where evidence was stored? Slide 40: Chain of Custody Documentation - Evidence exhibits are labelled during packaging/preservation and before submission - Chain of custody documentation: - Evidence labels - Notes or logs (evidence logs, easiest way to maintain chain of custody for your evidence, and each piece of evidence that you get is numbered with a placard-yellow numbered card-and that is photographed as well) - Final reports - Information required to prove chain of custody: - Name or initials of individual collecting evidence (and each subsequent contact) - Date of collection, date of transfer - Agency, case number, type of crime - Storage location - Description of item **Online Lecture Week 6: The Body as a Crime Scene** Slide 1: Pronouncing Death at a Crime Scene - First responders called when a crime scene or body is discovered - Upon arrival, priority is to preserve life - Must assume person is alive -Provide life saving measures or procure emergency medical assistance until qualified expert pronounces death - Police and other investigators not authorized to pronounce death - Only qualified medical practitioner (could be doctor in hospital or coroner) - Are exceptions... Slide 2: - Police may pronounce death where person is "obviously dead" - "Obviously dead" refers to: - Decapitation - Transection (when the body is transected, this often is seen at the waist, and occurs during motor vehicle collisions) - Visible decomposition (later stages + skeletonization) - Gross rigor mortis - Gross outpouring of cranial or visceral contents (refers to cranial contents being the brain-on the ground, visceral contents= guts of a person, if intestines are external to the body) - Gross charred body Slide 3: Death Investigation Process - Once death declared must notify coroner or medical examiner (ME) (they have legal authority or jurisdiction over the body) - **Coroner/ME have legal jurisdiction over the body** - Body may not be searched or moved without consent (can be done with permission from that coroner or medical examiner) - In Canada, coroners/ME's are responsible for overseeing the investigation into sudden death - *Coroners Act* - *Fatality Inquires Act* -i.e. Medical Examiners Act Slide 4: - In Ontario, s.10 (1) of Coroners Act (1990) requires deaths be reported if occurring: - As a result of: -Violence -Misadventure -Negligence -Misconduct -Malpractice - By unfair means - During or following pregnancy in circumstances that might reasonably be attributable thereto - Any death that is sudden or unexpected (like a motor vehicle collision) - As a result of disease or sickness not being treated by a legally qualified medical practitioner (a person hasn't been to the doctor in quite some time, ex. if a cancer patient hasn't been treated in the last 7 years, must be reported in accordance to the coroner's act) - As a result of any cause other than disease - Under any circumstances that may require investigation Slide 5: - In addition, must report: - Deaths of inpatients at designated institutions - Children's residence, psychiatric facilities, etc. - Deaths in long-term homes - Deaths on premises of a detention facility (doesn't have to be inmate, could be a visitor) - Any death during detention (if you yourself are an inmate) - Deaths that occurred while a person is restrained in a psychiatric facility, hospital, or secure treatment program - Work-related accidents at construction or mining areas -Large number of things that require reporting through the coroners act, legal obligation, doesn't mean an autopsy is necessary, the coroner will determine if an autopsy is required) Slide 6: Coroner vs. Medical Examiner - Coroner - Elected or appointed - No requisite educational standard, i.e., may or may not have a medical degree (most do though) - Canadian provinces: - ON, BC, SK, QC, NB, PE, YT, NU, NT - Medical Examiner: - Legally appointed - Medical degree with specialization in forensic pathology - Canadian provinces: \- AB, MB, NS, NL -In week one, we discussed that coroners will attend the scene, and pathologist perform the autopsy -This is because coroner doesn't have a requisite education standard, may or may not have a medical degree -They require someone with a medical background, like pathologists + ME Slide 7: Stages of Death Investigation - In Ontario, occurs in 5 stages: 1. Death reported to the coroner (done by qualified expert, and in rare instances, can be done by police) - Coroner decides whether to investigate - Attends scene to conduct preliminary examination -May call an expert (e.g. forensic anthropologist if the body is mummified-severely decomposed or skeletonized) -Transfer of legal authority of body via issuance of coroner's warrant 2. Coroner decides whether autopsy required - If yes, coroner issues coroner warrant to forensic pathologist authorizing postmortem examination - Forensic pathologist considers all information (may look at photos, medical records, they will perform their autopsy and consider those results, and input that into a report, and this report that allows the forensic pathologist to advise the coroner of the results of their investigation) - Circumstances surrounding death, autopsy results, etc. 3. Forensic pathologist advises coroner of results of their investigation Slide 8: 4. Coroner issues death certificate - Forensic Pathologist issues cause of death (although the coroner has legal authority over the body and is signing and issuing a death certificate, in Ontario, it is actually the forensic pathologist who completes the medical/legal autopsy and issues cause of death, coroner considers all of this when considering the death certificate-**not seen in popular media)** - Considers pathologist report and information from police 5. Regional coroner determines if case should be reviewed by someone else, or a coroner's inquest held (one regional coroner per region) - Coroner's inquest: conducted after accidental or unnatural death (the point isn't to poke holes, it is to rather review the case from start to end, aimed to promote better safety standards or other standards for the prevention of other scenarios in the future-so that similar deaths won't happen in the future, up to the regional coroner) -A judicial inquiry (hearing) among 5 jury members -Not adversarial -Highlight safety issues and prevention recommendations Slide 9: As we know, a death is reported and a coroner arrives, and that coroner is going to examine that body at the scene. They might look at positionality, what the person is dressed in, and look around for other things. Ex. is there a tool/weapon, is there blood spatter marks anywhere, not collecting evidence like the crime scene investigator would, more so observing the scene). - Following analysis of the body at the scene, it must be transported to the morgue - -Body Removal Services - Typically placed inside a body bag (to initiate medical/legal autopsy process) , put onto a moveable gurney - Continuity is important, continuing to establish that chain of custody - Police seal on bag zipper (police seal number is recorded by everyone involved-coroner, forensic anthologist ,other police) - In death investigation cases, often write on the body bag: -Scene location (address) -Case number(s)-provided by coroner, known as quinc number - Officer assigned to accompany the body to the morgue (typically for major crime) - Center of Forensic Sciences (Coroner's Complex)-where morgue is Slide 10: The Body at the Crime Scene - Evidence on the body, around the body, or the body may serve as evidence itself - Do not remove evidence from the body unless unstable (or evidence may become lost during transfer to the morgue) - The body ***[at]*** the crime scene can provide important information (ex. evidence on the body-hair found on the person that may lead us to a suspect) - Location and position of the body (simply by performing an external examination reveals a lot-coroner can look at where the crime scene is and how that body is positioned?) - E.g. Positional asphyxia? - Relationship of the body to other places of evidence - Environmental conditions over the span of that death scene - E.g. Temperature, humidity, etc. - Postmortem or delayed, or maybe decomposition is sped up or delayed, body can reveal this - General conditions of the death scene - E.g. Has the mail been picked up? Lights on or off?-Is the decomposition of the body congruent with how long its been since that mail was picked up? If there is a meal on the table is fresh but the body is severely decomposed, that tells us someone else was present at the scene. Slide 11: Defining Forensic Pathologist - "A branch of medicine that applies the principles and knowledge of the medical sciences to problems in the field of law." Slide 12: The Body as the Crime Scene: Forensic Pathology - Autopsy suite/autopsy bay - Forensic pathologists: - Medical doctors with specialization - Perform autopsies - May have expertise in other areas to assist in death investigation process - Seek to answer five main questions: - **Who** died? (identifying the deceased) - **When** did they die (postmortem interval-time since death) - **Where** did they die? (Is that consistent with where they are found?) - **How** did they die? - **By** what means did they die? Slide 13: Forensic Pathologist: PPE - **CSI Effect:** same thing applied to forensic pathology, often on TV, you see them wearing a single white lab coat and may be not wearing a mask, not reality, they are normally extremely protected - Crime scene investigators in attendance (often see CSI's in attendance of the autopsy on TV, that is not happening in reality. You might see criminal investigator such as a detective, may be at the scene at any major crime such as homicide or sexual assault, typically stand behind glass window)-Sometimes forensic identification present for major crime as well - Personal Protective Equipment (PPE) - Scrubs - Medical scrub cap covering all hair - Tyvek or similar 'apron' - Tyvek booties - Mask (N95) or even a face shield - Goggles or protective eyewear - Gloves (multiple)-nitrile gloves covered by nitrile elbow glove Slide 14: The Medicolegal Autopsy Process -The autopsy is not one process, however multiple. - Comprehensive medicolegal autopsy has three phases: 1\. Pre-morgue analysis - Knowledge of death scene, witness statements, and circumstances surrounding the death (before looking at the body) - Police, forensic nurses 2\. Morgue analysis (the autopsy) - Examination of body and associated trace evidence 3\. Post-morgue analysis - Microscopic and laboratory examinations following the autopsy - Forensic pathologist issues final autopsy report, which gets sent to coroner to sign death certificate Slide 15: Phase 2 Morgue Analysis - When body removed from scene, placed inside body bag with police seal over zipper - Photographs taken before body removed from body bag in the morgue - At receipt of the body in the morgue, the seal/body are removed from the bag (photo of seal, photo of seal broken at the center of forensic sciences as well) - Ensures continuity - Once the body bag is opened... - [Autopsy]: 1\. Evaluation of circumstances of death and medical history - May receive records from hospitals, doctor's offices, fire marshal, police, etc. 2\. Collection and documentation of trace evidence on/around the body - Pathologists, pathology assistants (will perform an external examination to allow for the collection and documentation of trace evidence on or around the body) - Forensic identification, major crime present Slide 16: 3\. Photographing and cataloging of injuries - Most facilities have an in-house photographer - Major crime: Forensic identification takes their own photos as well 4\. Detailed external examination from head to toe - Measurements (say of stature), note superficial marks on the body (scars, tattoos), medical interventions (is there a catheter or IV present?), nutritional status, postmortem changes 5\. Internal examination - Dissecting of organs and tissues - Obtainment of relevant samples - Tissue - Toxicology (fluid from the eyes, urine, blood) Slide 17: Cause of death vs. Manner of death - Cause of death - Trauma, event, disease, or illness that triggers the physiological processes resulting in death - Examples: -Coronary artery disease -Cirrhosis from hepatitis -Blunt force trauma to the skull - Manner of Death - Description of circumstances surrounding the cause of death - Categorized as: -Accident -Suicide -Homicide -Natural -Undetermined Slide 18: Manner of Death- Undetermined - What does 'undetermined' mean? - Not fitting into other designations or may fit into multiple designations - Manner of death may not be immediately apparent - Further testing or contextual information - Try to avoid (implies a lack of closure) - For example: - Forensic anthropology where not obvious blunt force or sharp focus trauma to remains Slide 19: External examination - External examination during autopsy may include documentation of postmortem state - Postmortem interval (time since death) - Cell death begins: - *Algor mortis* - *Livor mortis* - *Rigor mortis* - Simultaneously until 48 hours after death - Environmental and physical factors impact onset and duration of each stage Slide 20: - *Algor mortis* - 0-2 hours after death - Body loses heat - Body temperature falls to that of surrounding environment -Depending on the deceased person and the environment they are in: -Hot environment may accelerate postmortem changes -Cold environment may slow postmortem changes Both algor and livor mortis could be occurring simultaneously, that is why there is a time overlap Slide 21: - *Livor mortis* - 1-4 hours after death - Blood pools and clots in areas free of pressure -Dark, bruise-like pattern - Areas under pressure from items or contact with hard surface lighter in colour (under pressure, blood cannot pool and clot in that area such as lower back as it does not come into contact with the ground) - "Fixed" at approximately 4-6 hours after death - Lividity stays consistent - Onset used to assess postmortem interval - Informs us on the positionality of the body Slide 22: - *Rigor mortis* - 2-4 hours after death - While blood clots and settles in *livor* *mortis*, muscle cells cease aerobic functioning - Build-up of lactic acid - Causes chemical reaction that maintains muscle contractions (what we call *rigor mortis*) - Begins in small muscle groups within 2-4 hours - Larger muscle groups within 24 hours - Dissipates by 48 hours after death-someone who is in rigor is probably in the first 48 hours of their death Slide 23: Stages of Decomposition - Organized into consistent stages - Initial decay -Body intact, microorganisms active internally - Putrefaction -Rapid bloating (typically at the abdomen), intestinal tract ruptures, odour - Black putrefaction -Body collapses ('purge fluid'), flesh blackens, strong odour - Butyric fermentation -Fermentation and molding: flesh = cheesy consistency - Dry decay -Flesh hardens into leather-like texture - Skeletonization Slide 24: Internal examination - Begins with incision of torso (known as the Y-incision) - Tips of the shoulders, joining at middle of chest (where breast bone and sternum is), continuing to top of pubis - Soft tissue peeled back to expose bone - Chest plate is removed (consist of the sternum, manubrium, and the associated ribs, anything behind the breast and chest area to expose internal organs) - Organs removed - Block or "en-masse" method (take it out in one big block of fresh)-typically done when teaching - Independently (better to take out each organ independently) - Organs weighed and dissected to determine disease or injury Slide 25: - Examination of the brain: (typically done after the rest of the body) - Incision from behind the ears - Scalp peeled away from skull - Removal of skull cap - Brain removed; dissected immediately or "fixed" for dissection one week later (fixing refers to the hardening of something) - Fixing can happen due to the state of decomposition of the body, perhaps the brain has become gelatinous or liquified, which makes cutting the brain into cross-sections very difficult, fix the brain in formaldehyde to harden it) - During examination, sections of organs may be taken for subsequent analyses - Objective: cause and manner of death - Following dissection, organs placed back, body sewn and cleaned Slide 26: The Body as the Crime Scene: Review - **Who** died? - External examination and internal examination (e.g. medical records, DNA, medical implants, tattoos) - **When** did they die? - The mortises, stages of decomposition - **Where** did they die? - External examination and internal examination (trace evidence on the body, results of subsequent analyses) - **How** did they die? - Cause of death - **By** what means did they die? - Manner of death **Midterm study**: 1\. The scientific method as applied by the forensic sceientist: A 2\. Adipocere in dry, desert-like environments B, false 3.What is the correct order of lste-stage changes after death? C 4. D 5. B 6. How its used and indoor/outdoor Polar coordinates: use compass, record distance and cardinal direction of exhibit -best over large areas When answering the auestion "how did they die?" forensic pathologists are determeine: B cause of death (by what means caused their death) Manner (circumstacnes of how they died) Blank methods is best in tricky contexts and measures the loation of evidence from two fixed points: C triangulation The secondary crime scene: B. Is the seoncd site chronologically involved in a crime **Week 7-7a: Types of Evidence:** Slide 1: Defining Evidence: - '*Evidentia'*: to be visible - '*Videre"*: to see - Anything can be evidence, can be "invisible" too (think of fingerprints) - Evidence: "Any information or material relied on in legal proceedings to prove or disprove a fact or legal argument" Slide 2: Types of Evidence - \(1) Testimonial evidence - 'Oral evidence' or 'viva voce evidence' - Evidence given verbally by a witness during testimony - \(2) Documentary evidence - Consist of documents of any kind -Handwritten or mechanically produced (text messages, something photocopied, laptop, typewriter) -Example: medical records, affidavit - \(3) Real evidence - Physical evidence (generally covering items of non-living origin) - Biological evidence (any evidence that originates from a living source) Slide 3: Real Evidence - Some texts call this 'physical evidence' without further categorization - Evidence that crime scene investigators most concerned with - Collection and preservation at the crime scene - Analysis in the lab - Real evidence may be: - Physical - Biological Slide 4: Physical evidence (non-living origin) - Real evidence that is non-living in origin - For example: - Fingerprint originates from sweat, biological, DNA can be gathered - Glasses are non-living, - Fingerprints - Footprints - Fibers - Paint - Tire impressions - Firearms - Toolmarks - Glass Slide 5: Biological Evidence - Real evidence that originates from a living source - For example: - DNA and body fluids - Hair, skin, bone - Flora (ex. pollen) - Fauna (ex. insect larvae, maggots) - Plants - Animals - Examination and analysis may identify the living organism that deposited it - Important that crime scene investigators be aware of proper preservation and collection protocol Slide 6: Class Characteristics and Individual Characteristics - Biological evidence may be traced back to single source/common origin (DNA can be sourced back to one person) - Most often, physical evidence can only be associated with a group - Placed into a class -'Class characteristics' (ex. of class= looking for fiber, cannot link to the source, but could put it into the class of polyester material) - Individual characteristics: - Distinct differences that allow association with a single source -To high degree of certainty Slide 7: - Biological evidence as individualizing - For example: DNA analysis - Some physical evidence may be individualized: - For example: -Toolmark analysis -Bullet and casing comparisons -Tire impressions -Fingerprint analysis -Handwriting Slide 8: Other Classifications of Evidence - Three main types of evidence explored today: testimonial, documentary, and real evidence - Real evidence as physical or biological - Other terms to be familiar with: - Direct versus indirect (circumstantial) - Other classifications of real evidence -Associative -Indicative -Class, latent, and trace evidence Slide 9: Direct Versus Circumstantial - Direct evidence - Proves or disproves an important fact beyond speculation - Based on personal knowledge or observation - Refers primarily to testimonial evidence - Indirect or 'circumstantial' evidence - "Direct proof of a secondary fact which, by logical inference, demonstrates the ultimate fact is to be proven" - Relies at least partially on speculation but logically supports a fact - Refers to testimonial evidence and/or physical evidence -Ex. seeing people come into class with umbrellas, raining jackets-assumed it was raining, inferring the rain) - Most evidence examined in the crime lab is circumstantial Slide 10: Associative Evidence - Any real evidence that places an individual directly at the crime scene or as having had direct contact with the victim - Provides linkages between: -Suspect and victim -Suspect and crime scene -Victim and crime scene - For example: - Fingerprints at a crime scene - Strand of suspects hair on body of deceased Slide 11: Indicative Evidence: - Indicative evidence - Any real evidence which substantiates or proves that a certain amount of time has elapsed - Generally, no; for documentation - For example: State of decomposition, Weight loss of child during an abuse case - May be exceptions -For examples: entomology (indicative biological evidence) Slide 12: Class, Latent, and Trace evidence - Class evidence: real evidence that requires precise classification for use in Court - Requires classification into a more narrow range - Collective in nature -E.g. blood (can be furthered into blood group), semen, or hair (furthered into pubic hair, scalp hair) - Latent evidence: real evidence that is often not visible without chemical, photographic, or electronic development or enhancement (biological or physical that we can't see) - For example: Fingerprints - (Ex. hotel room and using blue lights) - Trace evidence: real evidence that must be extracted from another substance or item - Very small amounts - May be naked to the human eye - Ex. sperm extract seminal fluid and look under microscope Slide 13: - Class, latent, and trace all may describe physical or biological evidence - May be characterized in multiple ways - For example: -Evidence may be biological, associative, and trace -Evidence may be physical, trace, class, and associative - So how do we know what to call it? - Step 1: Establish evidence type -Crime scene investigators concerned with real evidence - Step 2: Physical or biological? - Step 3: What other classifications may apply? Slide 14: Importance of Real Evidence in Criminal Investigations - Real evidence is important for a number of reasons: - \(i) Linkage of persons, crime scenes, and/or objects -Locard's Exchange Principle (every contact leaves a trace) - \(ii) Providing essential information on facts of the case -*Corpus delicti* -"Body of the crime" or "element of the crime" -Establishment of proof through evidence that a crime has been committed -Must be proved by prosecutor -E.g. arson charge; corpus delicti includes evidence of fire and damage - \(iii) Revealing *modus operandi* -Preferred method of operation Slide 15: - Real evidence is important for number of reasons; - \(iv) Provide investigative leads - \(v) Prove or disprove witness statements (DV case, and arson, one individual says wife threw kerosene lamp at me and overnight there was a fire-forensic chemist could analyse if the substance kerosene or gasoline) - \(vi) Identify -Suspects (unknown or known) -Victims -Other crime scene locations - \(vii) Assist in reconstruction of the crime scene -Crime scene investigator usually more interested in "how" a crime occurred (think about blood splatter, dexter) Slide 16: Legal Issues and Evidence - Crime scene investigators must be familiar with the law and rules of evidence - What will or will not be acceptable - Burden of proving guilt on prosecutor - Crime scene investigator collects evidence - Overarching rule of Evidence Law: - Any relevant evidence should be admitted unless there is a rule of law or policy that requires exclusion Slide 17: Admissibility of Evidence - Reasons that a trial judge may deem something inadmissible: - Irrelevance -Evidence is irrelevant or immaterial to the issue before the Court - Unreliability -By its nature, evidence may be unreliable (i.e. hearsay) - Prejudice -Prejudicial quality of evidence: tendency to influence one in way that is unfair -Prejudice occurs when prejudicial quality of evidence outweighs probative value - Unfairness -Evidence must be obtained in a way that is fair (review: Search and Seizure in Canada) - Procedural unfairness -Procedural rules or other reasons that would be unfair to defense or confuse the issues **Week 7-7B: DNA and Body Fluid Evidence** Slide 1: Introduction to Forensic Biology - Serology: - The analysis of the properties and effects -Liquid state or dry state -Stain form (perhaps on a carpet) - Previously (pre-mid-1980's), could not individualize a sample - Could only indicates a strong personality - Introductions of deoxyribonucleic acid, or DNA - DNA extracted from body fluid evidence (often blood, seminal fluid, and saliva) Slide 2: Background to DNA: What is it? - Human body composed of trillions of cells - Inside almost every cell is a nucleus (contains structures known as chromosomes) - Nucleated cells have 46 chromosomes - 23 matching pairs -1 from mother, 1 from father - Chromosomes contain DNA - Thus, most cells contain DNA - Red blood cells do not contain DNA, white blood cells do contain DNA Slide 3: - DNA as a two-stranded molecule - Double helix - Compromised of chains of nucleotides - Sugar (deoxyribose) linked to phosphate, and - Base -Adenine (A) -Thymine (T) -Guanine (G) -Cytosine (C) - Hydrogen bonds between bases - Sequence of bases constitute our genetic code Slide 4: - Two kinds of DNA: 1\. Nuclear DNA: - Found in nucleus of cells - One copy per cell - Equal contribution from each parent - Unique to the individual -Most valuable in criminal investigation 2\. Mitochondrial DNA (mtDNA) - Found in the mitochondria of each cell - Many copies within each cell - Transmission through **maternal** line - Not unique to the individual -Use more limited Slide 5: Uses of DNA Evidence - DNA has revolutionized identification procedures and criminal justice - DNA evidence may be used to: - Identify a single person as the donor (confirming the people who hadn't committed the crime), rule other people out) - More correctly, eliminates almost all others - Rule out a suspect as the donor - Link a perpetrator to multiple offences - Identify the victim - Through DNA of close relatives Slide 6: Identification and Documentation of Bodily Fluids at the Crime Scene - Samples taken from a victim or suspect are biological samples - Samples taken from the crime scene may not be - E.g. stain on carpet: blood, wine, oil? - Presumptive tests tell crime scene investigators: - Whether a sample is a certain substance - That a substance is not a certain substance - Highlight an area that warrants further investigation -Prioritize areas for processing (search for actual evidence that's there) Slide 7: - Positive reaction from presumptive test must be subject to confirmatory test - May give false positive - Confirmatory tests performed by forensic biologists at a forensic laboratory - More timely - More expensive - More specific (done in lab) -Further rests may be required for individualized (cannot be done in an hour, CSI effect) Slide 8: Presumptive Tests for Blood - Presumptive tests for blood: - Colour spot tests -Rely on properties of hemoglobin -Hemoglobin: oxygen carrying molecule found in blood - Sensitive - Easy to perform Slide 9: - Guidelines for presumptive testing of blood at the crime scene: - Ensure sufficient samples available - **Never place chemical on the stain** -Rather utilize sterile swab or filter paper (chemical goes on swab, not stain, If you put on sample, can contaminate) - Positive and negative controls - Thorough documentation -Location -Date and time -Name of the CSI -Which test(s) performed -Lot number and expiration of chemicals Slide 10: Luminol - Sprayed and viewed using special light sources - Reacts to iron (heme) in blood - Will fluoresce -Done through a process called chemiluminescence (blood reacting to chemical) - Advantages: - Highly sensitive (can detect blood diluted 100 thousand times) - Does not interfere with DNA testing - Disadvantages: - Requires complete darkness - Faint luminescence - False positive to substances containing iron - Slide 11: Bluestar - Developed to overcome problems with luminol - Most crime scene investigators now prefer BLUESTAR - Advantages over luminol include: - Non-toxic - Total darkness not required - Stronger luminescence - Longer lasting reaction - Higher sensitivity - Also does not interfere with DNA analysis Slide 12: Hemastix - Originally to test presence of blood in urine - Colour change from 0-6 - 6= indicates presence of blood - Disadvantages: - Interferes with DNA samples - False positives with rust, bleach, and vegetable extracts Slide 13: Phenolphthalein (Kastle-Meyer) - Conducted on filter paper or swabs (a drop of reagent is placed on swab + a drop of hydrogen peroxide) - Reagent utilized with hydrogen peroxide - Colour change: - Pink in presence of blood - Disadvantages: - Interferes with DNA analysis -Do not test the stain itself -Swab stain, test swab - False positives: horseradish and potatoes Slide 14: Presumptive Tests f