Lecture 1&2 - Intro

Question 1

What did Edmond Locard say which formulated Locard’s exchange principle?

Answer 1

it is impossible to act, especially considering the intensity of a crime, without leaving traces if this presence.

Question 2

What other term refers to Trace Evidence?

Answer 2

Proxy Data

Question 3

What does Proxy Data provide?

Answer 3

links between people and locations or objects

Question 4

What type of evidence does trace evidence provide?

Answer 4

robust and complimentary evidence

Question 5

What is a main evidence type used nowadays that is not a form of trace evidence?

Answer 5

DNA

Question 6

Name 3 things trace evidence can help us do?

Answer 6

aid in reconstructing crimes
give investigative leads
be used as complimentary evidence to further support conclusions

Question 7

What is trace evidence?

Answer 7

smaller materials that are transferred during committing a crime that can help in forensic investigations

Question 8

What are the 3 main groups of trace evidence?

Answer 8

inceptive = has a crime been committed
identification = fingermarks and DNA
associative = has a contact occurred

Question 9

Trace evidence can not be unique but it can be…?

Answer 9

characteristic

Question 10

In what ways could trace evidence be transferred? (2)

Answer 10

contact transfer (1’)
non contact transfer
2’, 3’ or even 4’ transfer

Question 11

Absence of evidence doesn’t equal ……

Answer 11

evidence of absence

Question 12

What type of transfer may be easier to spot in a scene?

Answer 12

an addition compared to a removal

Question 13

In every case what does the value of the trace evidence rely on?

Answer 13

the context of the case

Question 14

What factors affect the persistance of trace evidence? (9)

Answer 14

environment temp, scene contamination, evidence tampering, weather conditions, emergency services involvement, water submersion, post deposition activities (e.g having a shower), material type, nature of contact

Question 15

what might promote evidence degradation? (5)

Answer 15

environment/weathering, animal/microorganism interference, crime to recovery time, recovery time to analysis time, how far the evidence is embedded

Question 16

what factors affect trace evidence transfer? (8)

Answer 16

material type, shedding of the material (some shed easier than others), pressure of contact, surface area of contact, time of contact, presence of sweat, porosity of materials, frequency (contact time and number of times of contact)

Question 17

Name some challenges associated with trace evidence (8)

Answer 17

emergency personnel intervention, scene tampering, evidence not found, evidence found but not relevant to the case, evidence found but its value not recognised, too much trace evidence found (don’t know what to prioritise), incorrect storage, incorrect collection method (results in loss or damage), bias (leading to inaccurate interpretation)

Question 18

Name three things used to avoid crime scene tampering

Answer 18

CAP - common approach path
log books to monitor who is going in and out of a scene
stepping plates

Question 19

What are some things that need to be thought about when recovering trace evidence? (4)

Answer 19

recover the whole item?
use gloves or tweezers?
is the sample wet or dry?
how should it be stored?

Question 20

what methods can be used to ‘lift’ trace evidence at a scene?

Answer 20

gelatine lifters, swabbing (wet swabs could interfere with the evidence), tweezers, tape, hinge lifters

Question 21

what type of evidence are gelatine lifters not the best for?

Answer 21

anything with DNA or proteins because gelatine is made of collagen and they could interact causing issues in the analysis

Question 22

What substances do fingermarks contain that are classed as trace evidence?

Answer 22

grease, proteins, drugs, cosmetics

Question 23

what type of trace evidence does ESLA collect?

Answer 23

dust