Chapter 3: Physical Evidence

Question 1

What are the 2 main forensic data bases?

Answer 1

1. Fingerprint Databases
2. DNA Databases

Question 2

What is physical evidence?

Answer 2

Encompasses any and all objects that can establish that a crime has or has not been committed, or can provide a link between a crime and its victim or a crime and its perpetrator.

Question 3

List a couple types of physical evidence

Answer 3

Blood, semen, and saliva
Documents
Drugs
Explosives
Fibers
Fingerprints
Firearms and ammunition
Glass
Hair
Impressions
Organs and physiological fluids
Paint
Petroleum products
Plastic bags
Plastic, rubber, and other polymers
Powder residues
Soil and minerals
Tool marks
Vehicle lights
Wood and other vegetative matter

Question 4

What does it mean for an object to be identification?

Answer 4

The object of an identification is to determine the physical or chemical identity with as near absolute certainty as existing analytical techniques will permit.

Question 5

What must an object undergo to be determined as identification?

Answer 5

Sufficient number of tests to exclude all other substances

Question 6

What are common types of identification? (objects, substances)

Answer 6

• Chemical composition of an illicit drug
• Residue
• Blood
• Semen
• Hair

Question 7

What is a comparative analysis?

Answer 7

A comparative analysis has the important role of determining whether or not a suspect specimen and a standard/reference specimen have a common origin

Question 8

What is an individual characteristic mean in broad terms?

Answer 8

Evidence that can be associated to a common source with an extremely high degree of probability is said to possess individual characteristics

Question 9

What is a class characteristic mean in broad terms?

Answer 9

Evidence associated only with a group is said to have class characteristics

Question 10

Why is class characteristics still useful? What is it mainly used for?

Answer 10

Can still help exonerated people, rather than identifying the perpetrator

Question 11

Class or Individual? The matching ridge characteristics of two fingerprints

Answer 11

Individual

Question 12

Class or Individual? White truck fleeing crime scene.

Answer 12

Class (Unless they have license plate or VIN etc)

Question 13

Class or Individual? The comparison of handwriting characteristics

Answer 13

Individual

Question 14

Class or Individual? The fitting together of the irregular edges of broken objects in the manner of a jigsaw puzzle

Answer 14

Individual

Question 15

Class or Individual? Plant DNA

Answer 15

Individual

Question 16

Class or Individual? The comparison of random striation markings on bullets or tool marks

Answer 16

Individual

Question 17

Class or Individual? Fingerprints

Answer 17

Individual

Question 18

Comparison or Identification? Fingerprints

Answer 18

Comparison

Question 19

Comparison or Identification? White truck fleeing the crime scene

Answer 19

Comparison

Question 20

Comparison or Identification? Footprints

Answer 20

Comparison

Question 21

Comparison or Identification? Cocaine

Answer 21

Identification (Identified that the white powder was cocaine)

Question 22

Why is the purpose of physical evidence in the long run?

Answer 22

To convict or exonerate someone

Question 23

What are the 5 main forensic databases?

Answer 23

1. The Integrated Automated Fingerprint Identification System (IAFIS)
2. The Combined DNA Index System (CODIS)
3. SICAR (shoeprint image capture and retrieval)
4. The National Integrated Ballistics Information Network (NIBIN)
5. The International Forensic Automotive Paint Data Query (PDQ)