CSI Chapter 7 and 8 Flashcards

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Questions and Answers

What is trace evidence?

A generic term for small, often microscopic material; it is physical evidence of contact.

This chapter discusses ways trace evidence is ____

collected, preserved, identified, and used

What is the Locard Exchange principle?

A concept of transfer; when a person comes into contact with another, small changes occur.

What is the importance of transferred trace evidence?

It links suspects to victims or locations. Signup and view all the answers

Who is the bad guy?

Suspect, perpetrator. Signup and view all the answers

Who is the good guy?

Victim. Signup and view all the answers

What does sources of trace evidence mean?

Places or hosts where trace evidence can be found. Signup and view all the answers

What are types of sources of trace evidence?

Clothes, footwear, on the body, tools, weapons. Signup and view all the answers

How can trace evidence stick to clothes?

Static electricity or caught in the fabric. Signup and view all the answers

What should be done with clothes as a source of trace evidence?

Allow wet clothes to air dry before packaging Signup and view all the answers

Clothes should be packaged in ____ bags.

paper Signup and view all the answers

If known samples from the scene have been collected as exemplars, they should be packaged with the suspect's clothing.

False Signup and view all the answers

What happens once the clothes have been put in a paper bag?

Submitted to the crime laboratory for careful examination. Signup and view all the answers

What if there is a hair or small fiber that could be dislodged on the shirt?

Carefully package it in a test tube, pillbox, or appropriate container. Signup and view all the answers

How to solve improper evidence handling by emergency medical personnel?

Educate police agencies to inform paramedics to cut off pieces of clothing. Signup and view all the answers

How to collect clothes from deceased victims?

Carefully examine the body for trace evidence before undressing. Signup and view all the answers

Next type source for trace evidence: what can be found on footwear?

Dust, soil, debris, vegetation, or bloodstains. Signup and view all the answers

How should shoes be packaged?

Individually packaged to avoid cross-contamination. Signup and view all the answers

What happens if there is soil stuck to the shoe?

Care must be taken to ensure that the soil does not become dislodged during transmission to the laboratory. Signup and view all the answers

Next type source for trace evidence: what can be found from the body?

Injuries, microscopic particles of gunshot residue, hair in rape cases, bloodstains. Signup and view all the answers

Study Notes

Trace Evidence Overview

Trace evidence refers to small, often microscopic materials that serve as physical evidence of contact, playing a significant role in investigations.
Important for linking suspects to victims or locations.

Collection and Preservation

Trace evidence is collected, preserved, identified, and used in forensic investigations.
Proper handling and storage of evidence are crucial to prevent contamination or loss.

Locard Exchange Principle

States that whenever a person comes into contact with another person or environment, materials are transferred, resulting in inherent trace evidence.

Types of Trace Evidence

Common sources include:
- Clothing: fibers, hairs
- Footwear: dust, soil, or bloodstains
- Body: injuries, gunshot residue, hair, bloodstains

Handling Clothing as Evidence

Clothes must be collected promptly to prevent loss of fibers.
Suspects should undress on clean wrapping paper to catch any falling evidence.
Use paper bags for packaging; plastic can promote mold and mildew.
Avoid shaking clothes during collection.
Wet or bloodstained clothing should be air-dried before packaging.

Evidence Collection Protocol

Known samples, or exemplars, from the scene should never be packaged with the suspect's clothing to maintain evidence integrity.
Items should be placed in secure containers (test tubes, pill boxes) if delicate evidence like hair or fibers is present.

Footwear Evidence

Shoes often carry dust, soil, debris, or bloodstains crucial for impression comparisons.
Shoes should be individually packaged to avoid cross-contamination during transportation.

Body Evidence

Close examination of the body can reveal trace evidence like gunshot residue, hair, or blood, especially in cases of violence or struggle.
Investigators should look for signs of struggle and use alternate light sources for better visibility of trace evidence.

Education and Protocols

It’s essential to educate emergency medical personnel on proper evidence handling during lifesaving measures.
If clothing is removed from deceased victims, a careful examination should precede their undressing to avoid losing valuable evidence.

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Description

Test your knowledge on trace evidence and the Locard Exchange principle with these flashcards from CSI Chapter 7 and 8. This quiz reviews key terms and concepts essential for understanding how trace evidence plays a role in crime scene investigation. Perfect for students and enthusiasts of forensic science.