Forensic Evidence Collection

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Questions and Answers

What is the primary goal of collecting evidence at a crime scene?

To determine the severity of the punishment

To understand the motives of the criminal

To prove the suspect's guilt

To support a successful prosecution (correct)

What is the main difference between evidence and proof?

Evidence is used in criminal cases, while proof is used in civil cases

Evidence is information, while proof is the effect produced by that information (correct)

Evidence is circumstantial, while proof is direct

Evidence is allowed in court, while proof is not

What is the function of evidence in court, according to the Florida Evidence Code?

To prove or disprove a crime, support or undermine other evidence, and help determine an appropriate sentence (correct)

To prove the innocence of the defendant

To determine the credibility of the witnesses

To prove the guilt of the suspect beyond a reasonable doubt

What type of evidence proves a fact without an inference or presumption?

Direct evidence Signup and view all the answers

What is the purpose of the rules and concepts of evidence?

To guide officers toward completing the investigation successfully Signup and view all the answers

What is a crime scene?

A site or sites where a crime occurred, including an area or areas that contain evidence from the crime committed Signup and view all the answers

What is the purpose of collecting physical evidence at a crime scene?

To prove that the suspect committed the crime Signup and view all the answers

What is the role of evidence in court, according to LE911.1?

To prove or disprove a crime, support or undermine other evidence, and help determine an appropriate sentence Signup and view all the answers

Why is it important to separate victims, complainants, and witnesses at a crime scene?

To prevent them from talking to each other Signup and view all the answers

What should you ask witnesses to do at the crime scene?

To stay at the scene for interviewing Signup and view all the answers

Why should you document the names, dates of birth, genders, races, addresses, and telephone numbers of all people involved?

To verify individual statements Signup and view all the answers

What should you do if separate rooms are not available to separate involved people?

Place them in the same room with their backs to each other Signup and view all the answers

Why is it important to ask victims or complainants to name potential witnesses?

To verify their statements Signup and view all the answers

What should you do if witnesses try to leave the scene or remain in the background?

Try to keep them at the scene for interviewing Signup and view all the answers

Why do multiple witnesses of the same event never recall the same details?

Because human memory is prone to errors Signup and view all the answers

What should you do to prevent involved people from coordinating their accounts of what happened?

Tell them not to talk to each other or discuss the incident with anyone Signup and view all the answers

What is the purpose of changing gloves between collecting each piece of evidence needing DNA analysis?

To prevent contamination of the evidence Signup and view all the answers

Why is it important to air-dry wet evidence before packaging?

To prevent deterioration of the evidence Signup and view all the answers

What type of analysis is used to examine trace evidence?

Microanalysis Signup and view all the answers

What is an example of a type of trace evidence?

Textile fibers Signup and view all the answers

Why is it important to use breathable containers for packaging wet evidence?

To allow air to circulate and prevent deterioration Signup and view all the answers

What is the purpose of placing each piece of evidence in its own separate container?

To prevent mix-up of evidence Signup and view all the answers

What is a potential source of fibers that can be transferred during a crime?

All of the above Signup and view all the answers

Why is it important to follow agency policies and procedures for evidence handling?

To prevent contamination and deterioration of evidence Signup and view all the answers

What is the purpose of the crime scene log?

To provide proof of crime scene security and validate evidence collection Signup and view all the answers

Who is responsible for documenting details in the crime scene log?

The officer posted at the access point Signup and view all the answers

Why are officers not assigned to the crime scene not allowed to access the scene?

Because they are law enforcement officers but not assigned to the scene Signup and view all the answers

What should be included in the report if evidence becomes contaminated or altered?

The original condition of the evidence and the events leading to its damage Signup and view all the answers

Who determines the crime scene jurisdiction for crime scene services?

The responding officer's supervisor Signup and view all the answers

What factors determine the number and type of personnel needed to process the crime scene?

All of the above Signup and view all the answers

What is the purpose of assigning shifts for officers at the crime scene?

To take weather and staffing limitations into consideration Signup and view all the answers

What is the role of the supervisor or investigator at the crime scene?

To coordinate duties and assign shifts for officers Signup and view all the answers

What is the first step to take when responding to fentanyl exposure at a crime scene?

Follow the protocols described in the First Aid chapter Signup and view all the answers

What is a document, in the context of questioned document evidence?

Anything containing a mark to convey a message Signup and view all the answers

What is the purpose of a chain of custody?

To document everyone who handled evidence Signup and view all the answers

What should you do if you suspect that money found at a crime scene is counterfeit?

Document the finding and collect the money as evidence Signup and view all the answers

What type of information is maintained in the FCIC/NCIC database regarding counterfeit currency?

Suspects under investigation and information leading to their apprehension Signup and view all the answers

Why is it important to carefully handle documents found at a crime scene?

To preserve the condition of the documents Signup and view all the answers

What is the purpose of document analysis?

To answer questions about the document's authorship and authenticity Signup and view all the answers

What should you do when you find evidence of any kind at a crime scene?

Begin a chain of custody to document everyone who handled the evidence Signup and view all the answers

Study Notes

The Crime Scene and Evidence

A crime scene is the site or sites where a crime occurred, including areas or objects associated with criminal behavior.
A crime scene can be a location, person, place, or object.

Function of Evidence

Evidence is anything that tends to prove or disprove the existence of a fact.
Evidence has three basic functions in court: to prove or disprove a crime, to support or undermine other evidence, and to help determine an appropriate sentence.

Types of Evidence

There are two broad types of evidence: direct and indirect (or circumstantial).
Direct evidence proves a fact without an inference or presumption and conclusively establishes that fact.
The crime scene log is a document that details the name, rank, and agency of each person entering or leaving the scene, the date and time of the person's entry or exit, and the reason the person was at the scene.

Processing a Crime Scene

Upon arrival, the supervisor or investigator will coordinate duties such as evidence collection, securing the scene perimeter, and other assignments.
The size and type of crime scene search determine the number and type of personnel or resources needed for processing the scene.
Agency policies, procedures, jurisdiction, and available resources will also factor into how to proceed.

Identifying Witnesses and Victims

Ask the victim or complainant who was present during the crime or event to name any potential witnesses of the incident.
Document the names, dates of birth, genders, races, addresses, and telephone numbers of all people involved.
Ask vital witnesses to stay at the scene for interviewing.

Separating Involved People

In a criminal investigation, victims, complainants, and witnesses must be kept separated to prevent them from coordinating their accounts of what happened.
Place people in separate locations, near the crime scene area, but in a place that poses no risk of contaminating evidence.

Personal Protective Equipment (PPE) and Evidence Collection

Depend on the type of evidence being collected, officers may need booties, facemasks, goggles, aprons, and other protective clothing or gear.
Change PPE as often as necessary to avoid cross-contamination.
Change gloves between collecting each piece of evidence needing DNA analysis.

Packaging and Handling Evidence

Use proper tools, equipment, containers, and packaging to prevent contamination and degradation of evidence.
For example, wet evidence, such as items soaked with body fluids or living plant material, must be air-dried, packaged in breathable containers, such as paper bags, or both.
Place each piece of evidence collected for DNA analysis in its own, separate container.

Trace Evidence

Trace evidence is small quantities of material transferred from a victim or suspect to each other or to a crime scene.
Trace evidence can include human hair, animal hair, textile fibers and fabric, rope, feathers, soil, glass, and building materials.

Questioned Document Evidence

A document is anything containing a mark to convey a message.
Questioned documents need examination to verify that they could be evidence.
Questioned documents may also contain latent fingerprints and DNA.

Chain of Custody

When recovering evidence of any kind, begin a chain of custody to document everyone who handled the evidence as well as when, why, and what changes, if any, were made to it.
A chain of custody documentation proves that the evidence submitted in court is the same evidence collected at the crime scene.

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Description

Learn about the rules and concepts of evidence collection at a crime scene to support a successful prosecution. Understand what type of evidence to look for and how to apply evidence rules to a crime scene and follow-up investigation.