1. Evidence
Forensics 352

2. Locard Exchange Principle
A cross transfer of evidence always occurs between suspect and victim or locale
Example : Murder by Numbers

3. What are the two types of evidence?
Direct Evidence
establishes a fact and does not make any inferences
Examples:
Confessions
Video cameras
Testimony of Witness *** Remember not very reliable but has big influence on the jury!!!

4. What are the two types of evidence?
Indirect Evidence; aka circumstantial
implies a fact without actually proving it
there could be another explanation for evidence being present
most evidence is circumstantial

5. What is circumstantial evidence?
Classified as physical or trace evidence
Physical
Trace
Seen by naked eye
YES NO
Use chemical methods or an alternate light sources to identify
Documented with photos
Processing
hair, bodily fluids, powders
Sources
blood shed, bullet casings

6. Class versus Individual
Class Evidence = object has characteristics common to a group of similar objects
Individual Evidence = object can be linked to a unique, single, specific source
Let’s take a look at some examples:

7. Class or Individual Example
A pistol was found in a theatre where a man was shot. A suspect known to have owned a Derringer like this one was apprehended. Would this gun be considered individual or class evidence?

8. Class or Individual?
Can it be determined whether theses bullets were fired from the same gun? How can bullets be individualized to a gun? Explain.