L7: physical evidence and lab

Question 1

list the different types of evidence

Answer 1

• associative
• class
• electronic
• latent
• trace
• circumstantial
• direct

Question 2

associative evidence

Answer 2

any evidence that places an individual at a scene or with the victim

Question 3

examples of associative evidence

Answer 3

• latent f.print left on an object
• semen from sexual assault
• paint transfer during automobile accident
• fibre left from contact with clothing items
• blood from physical injuries
• GSR

Question 4

class evidence

Answer 4

evidence that requires classification into a more narrow range

non-individualizing characteristics

Question 5

examples of class evidence

Answer 5

• overall f.print patterns
• size of shoe
• tire tread make
• shoe tread make

Question 6

electronic evidence

Answer 6

information and data transmitted and/or stored in any electronic devices

typically involved in crimes such as fraud or child pornography

Question 7

examples of electronic evidence

Answer 7

• computers
• cell phones
• USB/flash drives

Question 8

latent evidence

Answer 8

not visible to the naked eye without some form of enhancement or development [ALS or chemical treatment]

Question 9

examples of latent evidence

Answer 9

• fingerprints
• blood
• trace
• fibre

Question 10

trace evidence

Answer 10

extracted from another substance and is inn very small quantity [often not visible to the naked eye]

Question 11

examples of trace evidence

Answer 11

• fibers
• hair
• GSR
• paint

Question 12

circumstantial evidence

Answer 12

• evidence that relies on an inference to connect it to a conclusion or fact
• allows for more than one explanation, can be interpreted differently by different individuals
• most types of physical evidence fall under circumstantial evidence

Question 13

examples of circumstantial evidence

Answer 13

• fingerprints
• witness testifies they only heard the sounds of a gunshot and ran around the corner to find the defendant standing over the victim with a gun

Question 14

direct evidence

Answer 14

direct proof of fact

Question 15

examples of direct evidence

Answer 15

• eye witness account [i.e. witness testifies they saw the defendant shoot the victim]

Question 16

why collect physical evidence

Answer 16

• shows that a crime has been committed
• may show the key elements of a crime
• links suspect with the scene and/or victims [locard’s principle]
• corroborates statements
• exonerates the innocent

Question 17

can someone be convicted solely based on circumstantial evidence

Answer 17

yes [most evidence is circumstantial]

Question 18

what is locard’s exchange principle

Answer 18

‘every contact leaves a trace’

something is left, and something is taken

Question 19

how does cross contamination occur

Answer 19

when the biological or trace evidence from one evidentiary item contacts and contaminates another piece of evidence

impacts integrity, validity, credibility of the evidence and the handler

Question 20

how do you maintain integrity of an item

Answer 20

• package separately in paper bags
• evidence stored in secure lockers
• changing gloves during collection
• chain of custody

Question 21

describe chain of custody

Answer 21

a complete and unbroken record of the following information
- where was it located?
- who initially seized it?
- date and time it became evidence/seized
- who has possession of the evidence?
- what has been done to the evidence?
- where is the evidence currently being stored?