Week 4

Question 1

3 important factors in fingerprint photography

Answer 1

1) Proper exposure and illumination
2) Sharp focus (depth of field)
3) Fill the frame for max resolution

Question 2

How do you compare footwear impressions

Answer 2

Like-to-like

Question 3

Methods to create 2D test footwear impressions

Answer 3

1) Chemical pad and paper
- leaves no residue

2) Black powder and flexi vinyl (Mactac)
3) Black powder and transparent film
4) Ink and paper
5) Gel lifters
6) Large hinge lifters
7) Oily residue on outsole; paper; magna
8) Roller transport film and powder

Question 4

Methods to create 3D test impressions

Answer 4

1) BioFoam!
2) Sculpting putty (ie: playdoh)
3) MikroTrack
4) Snow/Mud/Dirt

Question 5

Physical match definition

Answer 5

Physical match occurs when:

Examination of the physical characteristics of 2 or more pieces of evidence reveals they are fragments from what was previously one continuous object and are therefore of a common origin

Question 6

Physical evidence comparison principles

Answer 6

1) Principle of uniqueness
- No 2 things…
- happen by chance exactly the same way
- constructed/made the same way
- wear the same way
- break in exactly the same way

2) Principle of Identification
- If proper methodoology is followed and there exists sufficient clarity in an object / impression it may be identified as originating from a particular source

Question 7

Class characteristics - Physical Evidence

Answer 7

Intentional or unavoidable characteristics that will be repeated and are shared by more than one object

Features inherent in an object acquired during manufacturing process

Colour, shape, size, style, model, pattern, diameter, thickness, number threads/wires, composition, texture, etc.

Question 8

Randomly acquired characteristics- Physical evidence

Answer 8

Something that is randomly added or taken away from the original structure of the object

Causes or contributes to making the object unique from all other objects sharing the same class characteristics

Cuts, tears, gouges, wear marks, striation marks, hackle marks, stress marks, randomly placed foreign marerial, etc.

Question 9

Comparison - 2 rules to follow for Physical Comparisons

Answer 9

1) Compare unknown to known
- Class characteristics then RAC’s

2) Compare like-to-like

Question 10

4 Possible conclusions for Physical comparisons

Answer 10

1) Inconclusive
2) Exclusion
3) Similar to
4) Identification