Crime Scene Evidence

• Crime scenes are locations, people, places, or objects linked to criminal behavior that contain evidence.
• Fingerprints, photos, physical evidence, and eyewitness accounts from a crime scene can prove a suspect's guilt.
• Properly collected evidence helps officers understand what occurred.
• Evidence rules and concepts guide successful investigations.

Function of Evidence

• The Florida Evidence Code (Chapter 90 of Florida Statutes) lays out basic evidence rules for criminal and civil proceedings.
• Evidence is anything that proves or disproves a fact.
• Evidence refers to information allowed in court; proof is the effect of that information.
• Evidence functions to: prove/disprove a crime, support/undermine other evidence, and help determine sentencing.

Types of Evidence

• Two main categories of evidence are direct and indirect (circumstantial).
• Direct evidence proves a fact without needing inference or assumption.
• Direct evidence examples include a driver admitting to speeding, speed measurement results, and eyewitness testimony.
• Indirect/circumstantial evidence needs inference/assumption to establish a fact.
• An example of indirect evidence is eyewitness testimony of a defendant entering a victim's home around the time of the crime.
• Evidence can be testimonial, physical, or documentary.

Testimonial Evidence

• This is a witness statement proving or disproving case facts, including testimonies from law enforcement, experts, and other witnesses.
• Testimonial evidence is generally less reliable than physical evidence because people perceive events differently, may not remember accurately or lie.

Physical Evidence

• Physical (real) evidence includes objects to prove or disprove case facts that directly participated in the crime.
• Examples of real evidence: trace evidence, biological/touch DNA evidence, impression evidence, firearms, electronics, chemical/toxicological evidence, and questioned documents.
• Physical evidence is less likely to give false results if identified, protected, collected, preserved, transported, and analyzed correctly.
• Physical evidence can be: fruits of the crime, instrumentalities, or contraband.
• Fruits of a crime are objects obtained due to committing the crime, like money stolen in a robbery.
• Instrumentalities are items used to commit the crime, such as a crowbar.
• Contraband is illegal property, like child exploitation material on a computer.

Documentary Evidence

• Documentary evidence is anything written or printed used to prove/disprove case facts, like bank or medical records, or a driver's history.

Admissibility of Evidence

• Admissibility refers to the legal requirements that must be met before evidence is presented in court
• Evidence must be relevant and real to be received by the court
• Admissibility of evidence protects constitutional rights, shields jurors from confusion, and speeds up trials.

Fruit of the Poisonous Tree Doctrine

• This doctrine allows courts to exclude illegally obtained evidence.
• Example: If an illegal interrogation leads to a murder weapon, the court can exclude both the interrogation information and the weapon.

Good Faith Exception Doctrine

• If a search warrant is believed valid but later found legally flawed, the court may still admit seized evidence.

Privileged Communication

• The Florida Evidence Code protects communications in certain relationships.
• Examples include communications between a sexual assault counselor/victim and a domestic violence advocate/victim.
• These communications are private, protected, confidential, and disclosure cannot be forced.

Securing and Protecting the Crime Scene

• Investigations determine incident events, identify/locate suspects, and develop probable cause for arrest.
• Preliminary investigations establish if a crime occurred, its type, when, and where.
• Initial incident reports should clearly document initial investigative steps.
• Securing, protecting, and preserving scenes to avoid contaminating evidence is the first priority.
• The second priority is to search for, identify, document, collect, and maintain physical evidence.
• Officer safety concerns, victim/witness injuries, and need for backup should be identified.
• The potential crime scene must be secured making sure the crime occurred within the officer's jurisdiction
• Crime scene size depends on the crime, evidence, and location.
• Burglary scenes can include an entire apartment complex or just one apartment.
• Attempt to locate and identify the point of the suspect's entry to and exit from the crime scene by visually inspecting the scene.
• Crime scene perimeters should be established, and unauthorized removal/alteration of evidence should not be allowed.
• Unauthorized people can damage, contaminate, or destroy evidence, and also put officer safety at risk.
• Scenes should be protected until they can be photographed and documented.
• People can be instructed to move behind crime scene tape, with refusal leading to arrest.
• Arrest is authorized for anyone crossing a marked crime scene area after a warning.
• Determine if the location is public or private property before entering to process evidence.
• Public property is open for public use; private property belongs to an individual
• Occupants of private property have an expectation of privacy needing a warrant or valid exception for entry.
• Officers can enter private property based on exigent circumstances, to sweep for suspects, provide aid, or prevent evidence loss before obtaining a warrant or consent.
• The primary officer/investigator designates entry/exit points and assigns an officer to maintain a crime scene log.
• The crime scene log details names, ranks, agencies of those entering/leaving, entry/exit times, and reasons for being there.
• The log provides proof of crime scene security and validates collected evidence.
• Officers not assigned to the scene do not have access because they are law enforcement.
• Contaminated evidence should be documented.

Managing Victims, Witnesses, and Suspects

• People on the scene must be identified.
• Identify all involved people; complainants, victims witnesses, and suspects, putting them into categories.
• Remember that different people can evolve; A victim becomes a suspect and a witness becomes a victim.
• All involved people should be separated to prevent discussing details.
• Separate family members during crisis situations using best judgement and empathy.
• Document who was injured, how, and with what.

Documenting the Crime Scene

• Photographing is the first event that should take place when documenting a crime scene.
• Photographs allow those not present, like the court/jury, to visualize the scene.
• Photos/sketches help victims/witnesses remember events.
• Crime scene photography moves from general to specific; overall, mid-range, and then close-up.
• Start at the perimeter, taking shots of the entire scene.
• Mid-range shots show the relationship between evidence items.
• Close-up shots detail specific evidence items and include a scale/identifier, usually a ruler or yardstick.
• The scale or identifier provides a form of measurement.
• Overall crime scene photos would be of the room from all four corners.
• Mid-range photographs would be photographs of the sofa.
• Close-up photographs would be the blood on the sofa.
• A ruler should be used to identify the size of the blood area.
• After taking pictures, check focus and lighting to avoid pictures being too dark or light which obscures detail which avoids glare and flashback from mirror glass
• Standard camera flashes project only 9-12 feet.
• Consider flood lighting with a flashlight or using your vehicle Spotlight or headlights if the overall picture requires photographing the scene from more than 9 to 12 feet away.
• Photographic framing is composing the photograph so that it depicts what you are trying to document.
• Overlap photos to show the relationship of items.
• Avoid including bystanders, officers, equipment, or pets.
• Flashlights can enhance lighting.
• Oblique lighting (side lighting) is used when photographing shoe/tire impressions or tool marks using alight at a low angle to show details by creating shadows.
• Extra batteries should be kept for cameras and flashlights.
• Agency-issued digital cameras with flashes should be used instead of cellphone cameras the court can subpoena information on your phone.
• Agency SOPs should be followed.
• Photographing perishable, transitory, or fragile evidence ensures documentation and preservation.
• Perishable evidence includes blood, footprints, tire prints, or trace evidence like hair/fibers.
• Transitionary evidence can be blown or washed away.
• Fragile evidence can include a bullet hole in glass held in place by Thin window tint.
• Photograph perishable, transitory, or fragile evidence first.
• Scales/identifiers (rulers, Miranda cards, dollar bills or coins) should be used when photographing specific items.
• Creating obstacle illusions should be avoided.
• Victims/witnesses can have visual evidence like bruises, lacerations, broken bones, gunshot wounds, blood, and trace/transfer evidence.
• Suspects don't have the right to refuse photographing injuries, such as scratches from the victim or blood evidence.
• Overall, mid-range, close-up perspectives are applied when documenting injuries and evidence on people.
• Crime scene sketches supplement field notes and photographs help with report writing.
• Sketches aid in reconstruction, explanation, and permanent incident recording.
• Sketches show positions of objects in relation to one another.
• If a sketch is going to be done, do it after photo uh photographing the scene and before beginning any detailed work.
• Photographs and sketches should be documented to avoid loss.

Evidence Handling Procedures

• The type of crime dictates what evidence to search for at a scene for example searching for evidence of illegal entry at a burglary scene.
• Use a systematic approach (pattern) for searching, dictated by the crime scene type.
• A grid search is often used indoors and this is a variation of the strip SL line search pattern; searches overlap a series of lines in a cross pattern making the search more methodical and thorough.
• A spiral search is usually used Outdoors by one person, the Searcher begins at a certain point and walks in increasingly larg in circles to the outermost boundary of the search area.
• A strip/line search is usually used Outdoors by several people, divide the search area into Lanes have one or more people search each lane by moving in both directions examining all areas.
• A Zone and quadrant search is used for vehicle searches both indoors and Outdoors or a large area, divide the area into four different sections and search each area using one of the patterns above.
• Victims, witnesses and suspects leave/take away evidence.
• Examples of evidence include fingerprints, shoe impressions, blood, fibers, hair, tool marks, paint scratches, broken glass, body fluids, controlled substances, electronics, equipment, computers, firearms, broken or damaged materials, tire track impressions, documents, and bones.

Types and Examples of Evidence

• Trace evidence can include hair, fibers, clothing, paint chips, transfer evidence, glass, wood, soil and dirt.
• Biological evidence includes blood, semen, saliva, bones, teeth, body tissues, hair, touch DNA.
• Impression evidence includes fingerprints, tire, shoe, footprints, bite marks, tool marks.
• Firearm evidence includes Firearms weapons projections gunshot residue cartridge cases tool marks.
• Electronic evidence includes cell phones, thumb drives, laptops, notebooks, tablets, computers, smart phones, external hard drives CDs DVDs VHS answer machines digital recording devices.
• Chemistry or toxical evidence includes blood alcohol levels drugs poisons.
• Questioned documents evidence includes checks bank statements address books wire transfers credit cards phone bills photographs or cameras, and photo copies.
• A triangle of evidence should be created by connecting the suspect and the victim to the scene.
• Talking to victims/witnesses helps determine evidence ownership.
• Evidence should never be handled with bare hands; universal precautions and PPE must be practiced.
• PPE should be changed often to avoid cross-contamination.
• Touching a victim, witness, or suspect before touching the crime scene could cause contamination.

Trace Evidence Details

• Trace evidence is small quantities of material transferred between people or to a crime scene.
• Trace evidence can include human/animal hair, textile fibers/fabric, rope, feathers, soil, glass, building materials.
• Microanalysis is trace evidence analysis with a microscope.
• Fiber transfers between clothing can come from anywhere.
• Paint transfers can help solve hit-and-run crashes to make sure that pain at the scene and the suspect's vehicle came from the common source.

Biological Evidence Details

• Biological evidence may contain DNA; all crime scene objects should be considered possible DNA sources.
• Common biological specimens include blood, semen, or saliva.
• Experts can identify body fluids and conduct DNA samples.
• Sexual assault cases may require examining semen evidence.
• DNA evidence can come from cigarette butts, drinking straws, soda/beer cans, masks, bottles, and bite marks.
• Teeth can also serve as identification and evidence.

Impression Evidence Details

• Working edges of tools leave marks on surfaces.
• Never try to fit a suspect's tool into a mark.
• Collect the entire damaged surface to compare with the suspect's tool.
• Fracture sites of broken, torn, or cut objects can provide strong evidence.
• Do not attempt to reconstruct items before fingerprints are processed.
• Footprints, shoeprints, and tire prints can link suspects.

Fingerprint Details

• All crime scene objects should be considered for fingerprints.
• Patent prints form from friction ridges/corrugated lines that are readily visible.
• Plastic prints are molded/embedded fingerprints visible on impressionable surfaces.
• Latent prints are the most valuable and common types of physical evidence at a crime scene.
• Latent prints are usually invisible and result from bodily residues Left Behind when the friction bridges of the hands or feet make contact with the surface.
• Wearing gloves and holding a flashlight are critical when collecting latent prints
• Holding a flashlight at an angle, lightly dabbing the powder, tapping and twirling, and lightly brushing from side to side are also critical steps
• Lifting tape must be applied when print is find.
• Tape must be lifted up and placed on the fingerprint card with all your information.
• Elimination prints help fingerprint analysts distinguish prints from victims, witnesses, or possible suspects, through taking fingerprints from everyone who may have been at the crime scene, to eliminate their prints from the pool of suspects.

Firearms Evidence Details

• Agency policies/procedures should be followed for handling firearms/ammunition
• PPE must be used to avoid contamination.
• Weapons should be secured, magazines removed, ammunition cleared, and the weapon should be documented
• Weapons must be placed in firearm evidence boxes, and ammunition in separate containers.
• Embedded bullets must not be removed from objects.

Electronic Evidence Details

• Electronic devices (cell phones, tablets, laptops, desktops) are common crime scenes and can store vital evidence and all media storage devices.
• Devices should not be manipulated to avoid damage.
• Computer evidence recovery is complex, needing specialized training.
• Cell phone information cannot be accessed without owner consent or a search warrant (Riley v. California).

Chemical/Toxicological Evidence Details

• Chemistry sections analyze substances for controlled substances listed under Chapter 893, Florida Statutes.
• A variety of controlled substances and drug paraphernalia should be able to identified by sight or odor
• Sharp objects, like needles/syringes, should be packaged in puncture-proof containers labeled "Warning: Sharps".
• Fentanyl or carfentanil are very hazardous substances. This can absorb through your mucous membranes in the mouth noise nose or eyes and they can be in powder form mixed with other types of drugs
• Overdose signs include disorientation, difficulty speaking/walking, slow pulse, nausea, slow/shallow breathing, or respiratory arrest.

Questioned Document Evidence Details

• A document is anything containing a mark to convey a message.
• Question documents need verification to verify that they can be evidence.
• Questioned documents may contain latent fingerprints and DNA.
• Money found at a crime scene requires following agency policy/procedures to avoid impropriety.

Chain of Custody

• A chain of custody should be started to document everyone who handled evidence, when, why, and what changes were made.
• This document proves that evidence in court is the same evidence collected at the crime scene.

Follow-Up Investigation

• An initial investigation should be reviewed to identify leads.
• A follow-up investigation can include contacting witnesses, victims, and potential suspects; reviewing evidence; locating additional evidence; and writing a Cap's request probable cause of David or arrest warrant.
• Review initial information and pursue leads for follow-up investigations.
• Incident reports analyzed and leads followed up on.
• Contacts developed through community policing can assist investigations.
• A field contact is a person contacted while on patrol, like a concerned resident or an anonymous complaint.
• Confidential sources furnish police with crime information, primarily for personal financial benefit/advantage and rarely out of a sense of civic duty.
• Documented confidential informants are confidential sources that officers recruit/manage based on agency guidelines.

Gathering Information on an Unknown/Known Suspect

• Modus operandi (MO) refers to a distinct pattern of criminal behavior or procedure used to identify someone.
• Crime patterns develop potential suspects by locating similar crime reports which helps narrow the field of suspects.
• Learning as much as possible about the suspect is critical by checking all their records.
• Private records of privately owned businesses or organizations, including privately owned utilities, are not open to the public law enforcement and require court orders to access them.
• Public records of government entities and publicly owned utilities are records that with few exceptions you may access on demand.
• Information access on juvenile arrest and incidents are restricted, and there may be limits on its use.
• Constant contact with dispatch when physically searching for wanted people should be maintained and update your location and status for Officer safety.

Show Up, Photographic Array, and Photo Lineup

• A show-up presents a possible suspect to a witness for identification at or soon after the incident and near the crime scene by officers who identifies the potential suspects in immediate situations of sudden battery or sudden snatching and results in immediate arrest.
• Potential suspect should not be moved to bring them to the victim or witness.
• A lineup should become a part of your follow-up investigation when a show-up is not a consideration or is unsuccessful.
• Lineups can be live or photo lineups, and Florida law provides requirements for both.
• A live lineup displays a group of people to a victim/eyewitness for identification of the perpetrator.
• Live lineups need additional people who look similar to the suspect, which is resource intensive.
• A photo lineup displays a photo array to victim/eyewitnesses for identification of the perpetrator.
• A photo array is a selection of photographs compiled to show to a victim or or eyewitness in a non-suggestive manner in order to identify a suspect when used in a photo lineup and is an efficient tool.
• Compiling a number of photographs of people who look similar to the suspect is easier than assembling a group of people similar to the suspect.

Lineup Administration

• A lineup administrator conducts the lineup, preferably independent from the investigation or unaware of which person in the lineup is the suspect
• Administer lineups using automated computer programs, preventing administrators from seeing the lineup until after the procedure is complete.
• Another option is randomly numbered shuffled folders containing photographs which prevents the lineup administer from seeing which photographs correspond to specific folders until after the procedure is complete.
• Number all photographs and filler photographs using the array before presenting the array to the victim or eyewitness
• Photo lineups can occur simultaneously or sequentially.
• Simultaneous presentations occur when the administrator presents a group of photographs all at once, and the administrator can instruct the victim or ey witness to Mark which photograph is a suspect and have the victim or I witness sign and date the array.
• Sequential presentation occurs when independent administrator presents individual photographs to the victim or eyewitness one at a time.

Acknowledgement

• Standardized instructions will need to be read to the victim or eyewitness to ensure consistent administration of the footo lineup along with The Florida Statutes mandate using these instructions; Additional procedures may need to be adhered to based on the agency policies and procedures
• Instructions should include: The perpetrator may or may not be in the lineup, the lineup minister does not know the suspect's identity, should not feel compelled to make an identification, it is important to exclude innocent persons as it is to identify the perpetrator, and the investigation will continue with or without your identification .
• Document or record word for word any comment that the victim or eyewitness makes during the entire lineup process and Note any non-verbal communication or action of the victim or eyewitness in the investigative file
• Document the precise photograph they select and preserve the entire photo Rus evidence document the process and the forms used in lineup in the investigative file if the victim or eye witness makes an identification or if the victim or eye witness is unable to identify a suspect.

Testimony

• Testifying stress can be mitigated through thoroughly reviewing all available case documentation and discussing the case with the appropriate agency personnel.
• Potential weaknesses in the case can be reviewed so the prosecutor can effectively deal with known problems by pointing out any conflicting statements or problems in the documentation of evidence
• Case file reviews should include all reports, photos, videos, evidence, and chain of custody.
• Testimony can take place in attorney's office, in the judge's Chambers, or on the witness stand in the courtroom.
• Involved parties will usually refer to attorneys as counsel.
• A professional demeanor should be shown by dressing in uniform.
• The rule of sequestration forbids witnesses from discussing the case with anyone but involved attorneys, and witnesses should not have any contact with the courtroom when other Witnesses are giving testimony Florida law states that you must follow the judge's orders completely when they invoke or impose the rule violating the rule of sequestration May mean the judge May penalize or punish the witness.
• Truth when providing answering questions is required through making an oath or affirmation before testifying.
• Questions should be listened to carefully, and you should pause and collect your thoughts before answering to look directly directly at the attorney or judge while only answering the question asked and never volunteer additional information.
• Suggestions to enhance testimony or strengthen a case should be avoided as you could be committing perjury, and do not alter an answer to match someone else's to avoid bias, prejudice, and plain language which could can destroy credibility.
• As with depositions, attorneys may occasionally pose improper questions.

Cross Examination

• Attorneys may use a variety of tactics during a criminal trial to discredit misrepresent or confuse you
• Defense tactics include:
  • Giving the impression that you are inept unreliable or lacking in confidence. Giving the impression that you are inept, unreliable, or lacking in confidence.
  • Being confrontational or badgering you to make you angry or affecting logic and calmness.
  • Firing questions of you rapidly to get as much information as possible and to lull you into a false security.
  • building report to create answers that favor the defense by mispronouncing your name forgetting your title or verbally demoting you or implying that you are of little significance.
  • drawing conclusions or assumptions making an assumption suggesting a response.
  • demanding a yes or no answer to a question that needs explanation.
  • reviewing reversing or rephrasing your words.