Forensics Midterm Review Ch.2 Scene investigation and Evidence collection

Circumstantial evidence

Indirect evidence that suggests the existance of a fact but doesnt directly prove it

Trace Evidence

-Physical evidence that is found at a crime scene in small but measurable amounts

-materials transferred between people, objects, or the environment during a crime

-Ex: fibers, hair, paint chips, gunshot residue

Direct Evidence

From video cameras/surveillance, eyewitness reports

Class evidence

A type of physical evidence that can be used to narrow down a group of people or suspects, but cannot identify the individual

Individual Evidence

Physical evidence that can be linked to a single, unique source with a high degree of certainty

Ex: fingerprints, DNA profiles

Physical Evidence

Any tangible object that can be used to link a suspect or victim to a crime

Biological Evidence

A type of evidence used in forensic science that includes bodily fluids and tissues, and is often used to solve crimes

Primary Location

The original location of a crime or accident

Secondary Location

An alternative location where additional evidence of a crime may be found

What is Locard's Principal of Exchange

When two objects come into contact with eachother, there it an exchange of materials between them

What are the Seven S's of Crime Scene Investigation

1. Secure the scene

2. Separate

3. Scan

4.See

5. Sketch

6.Search

7.Secure the evidence

Types of search patterns

-spiral

-grid

-linear (best suited for large outdoor areas)

-quadrant

What is a Paper Bindle

A folded piece of clean paper used to contain trace evidence at a crime scene, such as hairs, fibers, or paint chips.

-Also known as a druggist fold

How do you have to package liquids and arson remains

Unbreakable airtight containers

How do you package most biological evidence such as blood, saliva, and semen

A paper bag or envelope and kept dry at room temperature

How should dry evidence be packaged

A paper bag or envelope or paper bindle

What do fake or staged crime scenes include:

-arson

-burglary

-murder staged to look like a suicide

What are forensic lab technicians

Highly specialized scientists who handle only one type of evidence

chain of custody and what should you never do

1.Original evidence bag

2.Opened evidence bag maintaining signature on the first seal

3. Original evidence bag with uncut seal and signature, updated chain of custody in a new sealed and signed evidence bag

*NEVER open the evidence bag at the original seal