Types of Evidence

1. Types of Evidence Mrs. Crawley Fall 2009

2. Types of Evidence • What are some types of evidence that might be found at a crime scene? • Classifying Evidence (3 Categories) • Direct Evidence • Physical Evidence • Trace Evidence

3. Direct Evidence • What is Direct Evidence? • Def: Evidence that is observed by an eyewitness • Eyewitness • Def: Person who directly observes an event • Example: store clerk after being robbed • Can testify in court • Give accurate description of what they saw

4. Direct Evidence • Any problems……? • Description by eyewitness may not match • Example: car color • Reason: physical abilities, experiences and emotions affect our observations • Example: Car may look red but is grey to someone who is colorblind • May have to recall information over long time periods • Can you remember what you ate Sept. 4th?

5. Examples of Direct Evidence: Mug Shots & Line Ups • What is a line-up? • Def: Group of similar-looking people used to isolate a suspect • When is a line-up useful? • When there is a likely suspect • Line-up must be fair…..how? • Can a line-up be misleading? • Hard for a witness to pick out suspect • Suspect may not be present in line-up

6. Examples of Direct Evidence: Mug Shots & Line Ups • What is a mug shot? • Def: A picture of someone who has been arrested • Front & side view • Same rules apply from line-ups • Must look at photos of similar-looking people • Would mug shots be useful for a crime without a suspect? • What about if it is a crime in a large city like New York?

7. Examples of Direct Evidence: Mug Shots & Line Ups • Modus Operandi (MO) • “Mode of Operation” • Def: The way someone approaches a task • Example: Working alone, targeting older people, etc… • Allows Police to speed up mug shot process

8. Examples of Direct Evidence: Artist, Camera, Computer Software • How do we find a suspect if they’ve never been arrested (no mug shot)? • Forensic Artist • Def: someone who uses observations from people to draw a sketch of a person (victim or suspect) • Surveillance Camera • Def: Public camera used as security watch (time & date) • Facial Recognition Software • Def: software that matches video images to mug shot • Search 60 million images a minute based on facial features

9. Examples of Direct Evidence: Forensic Art • Forensic Artist • Use very distinct observations from witnesses • Example: Wide-set eyes, pointed nose, thin eyebrows, broad cheekbones • http://www.youtube.com/watch?v=jIXa8Ze7Mhk • http://www.youtube.com/watch?v=K8CljYn_7Mc • 1995 Oklahoma City Bombing • Timothy McVeigh • Software Available • Very limited in choices • Most artist prefer to free-hand sketch

10. Physical Evidence • What is physical evidence? • Def: Evidence that is present at a crime scene, on a victim, or in the suspects possession • Examples: • Paint • Glass • Explosives • Ballistics • Fracture matches • Impressions • Skeletal Remains

11. Trace Evidence • Trace Evidence • Def: Evidence that is left behind or picked up • Found in small but measurable amounts • Examples: • Skin • Hair • Fingerprints • Body Fluids • DNA • Dust/Dirt