Crime Scene Investigation: Chapter Two

The Crime Scene

• Chapter Two discusses the "crime scene", and all important aspects of ensuring the crime scene is preserved and processed correctly.

Key Terms

• Several key terms have been determined to be important for understanding:
  • Buccal Swab
  • Chain of Custody
  • Finished Sketch
  • Physical Evidence
  • Rough Sketch
  • Standard/Reference Sample
  • Substrate Control

Amanda Knox Case

• Amanda Knox, an American student, was involved in a controversial murder case in Italy.
• In September 2007, Knox moved to Perugia, Italy, as a foreign exchange student
• Knox shared an apartment with Meredith Kercher and two other women
• She became romantically involved with Raffaele Sollecito, who she'd often spend the night with
• On November 1, Kercher was found murdered in her bedroom, covered in blood and with stab wounds
• Knox and Sollecito were charged with murder and sexual assault, creating an international media storm
• Knox was convicted of slander, sexual violence, and murder and sentenced to 26 years in prison
• Her conviction was overturned four years later by the Italian Supreme Court, and a new trial was ordered
• The case against Knox in the original trial hinged on a bra clasp and a kitchen knife
• The kitchen knife - found in Sollecito's kitchen, had Kercher's DNA on the blade and Knox's DNA on the handle
• The bra - allegedly belonging to Kercher, was reported to have Knox's DNA on the clasp
• Defense experts questioned the DNA lab's procedures and crime scene management during the appeal process after evidence review
• It was found by authorities that Italian authorities failed to properly control, document, and preserve evidence at the scene
• For instance, the bra wasn't even taken during the initial crime scene search, but 40 days later
• The Supreme Court of Cassation in Italy cleared Knox and Sollecito in 2015, citing potential evidence contamination
• After assessing the evidence, the court saw "stunning flaws in the investigation and increased media attention"
• There were no "biological traces" linking Knox and Sollecito to the killing
• Rudy Guede, a third suspect who had fingerprints in Kercher's bedroom and DNA on and inside Kercher's body, was found guilty of murder and is still serving time

Physical Evidence

• Crime laboratories rely on physical evidence
• Physical evidence includes any objects that prove whether a crime has occurred or connect a suspect/victim to a crime
• Physical evidence's presence needs to be identified quickly to aid the investigator efficiently
• The scientist would be overburdened if every natural and commercial object in a crime's proximity were gathered
• Physical evidence is most valuable in criminal investigations when gathered with a collector's in-depth knowledge of the crime laboratory
• Forthcoming chapters will discuss ways for scientists to assess physical evidence
• Technology has increased the capabilities of crime laboratories, but investigators should not be complacent due to these developments
• Crime labs alone do not solve crimes
• Thorough investigations conducted by professional police officers lead to more solved cases
• Though forensic science is important, it is only one piece of an investigation
• Investigators must recognize physical evidence and properly preserve it for lab examination

Securing and Isolating the Crime Scene

• The first officer at a crime scene preserves and protects the area
• Officers should rely on their training to handle any dangerous situations
• Note any vehicles or people leaving the crime scene
• First priority goes to medical assistance and arresting the perpetrator
• Unauthorized people must be excluded from the scene ASAP
• Medical workers should approach a body indirectly, to avoid disturbing evidence
• The first responding officer evaluates the victim and records any statements
• Figure 2-1 shows the isolation of the area in practice with measures to close off the scene.
• The boundaries should include the crime's center, entry/exit routes, and areas where evidence may be discarded
• Ropes, barricades, and guards prevent unauthorized access
• Suspects, witnesses, and other individuals on scene must be identified and detained
• Exclude unauthorized personnel, including friends/family of the victim
• Only assigned investigative personnel should be admitted
• A log of who enters/exits and when must be kept by responding officers
• Excluding unauthorized staff may be difficult
• Violent crimes draw more attention from curious individuals
• Every entrant is a possible destroyer of physical evidence
• An officer in charge of protecting the crime scene requires the power to exclude all officers not directly involved in the investigation
• Always remember crime scenarios where the horde trampled on physical evidence
• A well-trained crime-scene investigative team must isolate the crime scene
• After securing the location, a lead investigator will assess the scene; determine scene perimeters
• The investigator logically deduces the clear items of crime-scene evidence
• Document and photograph obvious evidence, then take a walk-through to develop a method to examine/document the scene
• Ferguson, Baltimore, Cleveland, and Staten Island racial unrest has increased body-worn camera issues
• A tiny clip-on camera seems like an easy method to secure crime scene efforts; although implementation has many concerns to iron out
• Law enforcement has not universally accepted body-worn cameras or implemented management protocols for them
• One main concern for body-worn cameras is secure data storage and data management, but the devices do not replace digital/video cameras

Altering the Scene

• Personnel are not to do anything in the scene which alters it
• Aspects of the scene should not be disturbed unless they pose an urgent threat
• There should be no opening or closing of faucets or flushing toilets at scenes
• Officers should not adjust windows, doors, or the heating/air conditioning, as this can alter temperature conditions

Recording the Crime Scene

• Investigators have limited time at an untouched crime scene
• Crime scene opportunities should not be lost.
• Records are useful for investigations, but mandatory at trial to show the condition of the crime site and evidence location
• Crime scene recording is achieved via notes, photography, and sketches
• All three should ideally be employed, but financial/personnel limitations can restrict the use of photography in some cases
• Sketches and notes should always be taken, however
• Notes should begin with the call to scene investigation, and include the caller details, time of contact, and disclosure, alongside the case number
• The lead investigator records arrival date/time, those who are present, and the names of any other personnel contacted
• Keep a record of personnel leaving and entering the scene
• Record tasks assigned to team members, starting and ending times
• Investigators take initial walk-through prior to sketching, photograhing, and searching for evidence
• During the walk-through, record notes on aspects of the crime scene in its original untouched condition
• The notes should be uniform, written in ink, and kept in a bound notebook
• Ensure that notes are not based on memory, but are contemporary written at the same time as the crime scene investigation
• After the evidence search, team members mark the location of all evidence and describe it in their notes
• In homicides, the investigator should observe and record the state of body before medical examiner or coroner handles it
• Record suspects or victims
• Audio notes are kept by digital voice recorders, and then copied physically to a disk
• Narrating a video of the crime scene to combine these methods of documentation is an option
• Crime scene checklists should be filled out during the documentation to ensure all jobs are completed

Photography

• Photographing a crime scene has one main rule - it must be unaltered
• Position of evidence should be taken using overviews and close-ups
• The objects themselves should be taken in close-up
• A ruler or scale should be present to indicate signficance
• Four photographs are needed at minimum: overview shot, medium range shot, close-up photograph, and clsoe-up with scale
• This photographic series creates a good visual record of the position of all evidnece
• New cameras which take dozens of photographs by scanning can create a 3D model of the scene
• Cameras capable of producing 3D scan locations from multiple data are used
• Video is used and can be done by digital means, too
• All relevant areas should be taken using digital video, as well as close-ups
• An investigator narrates with one doing the shooting

Body Worn Cameras

• Police and the community have seen a relationship disruption over excessive force and failure to collect evidence
• Many cases are brought by witnesses
• Body Worn Cameras (BWCs) offer a potential method for police to record and document their actions
• President Obama pushed for federal involvement for training for BWCs in support
• Technology should result in legitimacy and accountability in this regard per these BWCs; these cameras record audio and video footage and allow for computer use, recording with a single button
• BWCs offer efficient tool for collecting evidence; offer medical help. BWCs can also record the officer performing various tasks
• The scenes are often difficult and locations often contain hundreds of evidence
• BWC should help in these efforts

Sketches

• Sketches in crime scenes serve many purposes pertaining to the legal investigation
• The sketch helps to show the indoor or outdoor crime scheme and offers a view of features related to investigation
• Possible pathways through crime scene should show with sketch
• Making exact sketch when lacking time is often a problem; rough sketch is okay
• Accurate dimensions are important
• The use of sketching kit helps

Finished Sketch

• Accurate sketch must involve care and concern, reflecting all the rough measurements
• Computer software helps in making diagrams
• These can involve intricate details such as blood spatter

Systematic Search for Evidence

• In reconstructing any crime, the investigator needs to look over evidence and oversee anything
• Some agencies have field evidence to search; they have equipment and skill to examine crime
• How one conducts such a search will deal with the location
• One needs to oversee the collection in case of need for duplication of effort

Search Patterns

• One or two investigators should utilize strip or line search pattern and move from one side to another
• This works best when perimeters are known
• The boundaries must be well established in order for method to be effective
• The grid search is very thorough and employs tow people performing lines through all axis corners
• This can only work when the corners are well established
• Spiral pattern involved investigator inward/outward
• Wheel or ray search pattern involves a set of groups searching rays to their centers. This is not preferred as it leaves areas between "rays" unsearched.
• Quarant or Zone methods breaks a scene into zones; each team will be assigned. This search type suits larger areas.

Locating Physical Evidence

• Search may center on the weapon and assailant - linking suspects to crime scene to help make case
• Vehicle search is detailed; the car has an under carriage that is important to scrutinize

Collecting and Packaging Physical Evidence

• Physical evidence ranges from smaller traces of crime and can be discovered in lab later on
• Collect things like hair to help the processes
• Clothing item should be carefully handled and wrapped separately
• Vacuums with filters to find evidence are good tools
• Scraping under the victim's nails with toothpick can be used for micro exam
• Physical evidence must extend beyond crime scene to autopsy
• Medical examiner carefully examines victim to determine death cause
• Tissues are then retained
• Evidence technicians handle mobile crime laboratories
• These can carry necessary items for protection, photos, collections, and fingerprint processing

Handling Evidence

• Investigators must manage to process the evidence in a way that doesn't alter anything from its time on scene to time in laboratory
• Disposable protection like gloves should be used
• Clean and sanitize equipment between uses
• Don't move or document anything until documentation on appearance is found
• A good idea is to submit entire item to laboratory
• Forceps can also be used
• Remove specimens appropriate; a blood stain may need to scrape the surface
• Well-prepared collectors are a boon

Packaging Evidence

• A variety of tools are often with a collector
• All different items go to collection separately; avoid damage
• For anything biological, use disposable tools; accumulation can lower value; paper packaging is easy to write on but can be sturdier per the item.
• Use a red biohazard sticker which ensures handlers recognize the blood samples, etc

DNA Evidence

• DNA can be used to help make the subject easier; the technique is helpful for this task
• Search anything touching victim
• Bed sheets with cells to find the issue

Best Practicce for Biological Evidence Packing

• Use bags, papers, cardboard, etc
• All are helpful for wrapping
• Evidence is sealed to prevent the transfer and contamination
• Seal in a way that causes alteration if it is tampered with
• Each item must be packaged separately
• Biohazzard labels must be present
• Plastic bags are not preferred; if wet, use an impermeable setup
• Seal packages and add label

Contamination

• Contamination is number-one concern for collecting DNA (via coughs, sneezees, etc)
• Always use face mask during collection for instance
• Coveralls also recommended

Chain of Custody

• Continuity of possession must make the trial
• Standard procedure is a guarantee of the evidence
• Those who handled the device must be accounted for; failure is a major mistake!
• Carefully package all items
• Label collector initials, as well as the date, on the article iteself
• Record things in appropriate forms
• It's helpful to obtain Standard/Reference Samples for items including glass, hair, and blood

Standard/Reference Samples

• Investigation may include paint from suspect vehicle
• It's important to make samples from these actions

Substrate Controls

• Substrate Controls have items that are materials from close distance
• Investigators ensure a surface has had gasoline exposure
• Thorough collection measures are good
• Evidence is given to a laboratory or to the mail
• Care is necessary to ensure it's not in transit to the laboratory

Crime Scene Safety

• AIDS increased due to crime; body fluids have affected this; precautions must be used
• Gloves and masks must be used in these cases