Footwear

Question 1

What is some information footwear impression evidence provide?

Answer 1

Number of suspects
POE and POX
Links between crime scenes
DOT in and out of crime scene

Question 2

What are the 2 types of 2D footwear impressions?

Answer 2

Transfer (positive) impressions

Take-away (negative) impressions

Question 3

What are the 2 types of origins of footwear impressions?

Answer 3

Dry origin

Wet origin

When in doubt assume the impression is a dry origin

Question 4

What is the difference between grazed lighting and oblique lighting?

Answer 4

Grazed - parallel to the surface

Oblique - not parallel, between 0 and 90 degrees

Question 5

What are some non-destructive methods of searching for footwear impressions?

Answer 5

Existing lighting
Strong lighting - oblique or grazed
ESDL - Electro Static Dust Lifter

Question 6

What are some destructive methods of searching for footwear impressions?

Answer 6

Powders - but can use on wet origin that has dried on hard surfaces

Chemicals

Question 7

How are 2D footwear impressions recorded

Answer 7

Photograph - overall, mid range, close up and ACAP

Be sure to use a tripod for ACAP

Question 8

How do you preserve 2D footwear impressions?

Answer 8

ESDL
Gel Lifters
Adhesive lifters

Photograph the lifts - mark with a backwards F to show it is laterally reversed (overall and ACAP)

Question 9

How are 3D footwear impressions recorded?

Answer 9

Photograph impression with L ruler at the lowest depth
Overall, mid range, close up and ACAP’s.

ACAPS - take 9 photos. 3 at different heights of oblique lighting on three sides

Question 10

How do you preserve 3D footwear impressions?

Answer 10

Dental stone

Prill Sulphur

Can you primers or snow print wax on snow. Can also use hairspray on some surfaces that are delicate

Question 11

What are some things to think about when taking test impressions?

Answer 11

Try to replicate same amount of pressure when unknown impression was made- may need to put the shoe on
Try to use similar substrate
DO NOT remove any debris from tread before doing test impression

Question 12

What are the methods that can be used to create 2D test impressions?

Answer 12

Chemical pad and paper
Powder on mactac or flexi vinyl (use correct colour powder)
Ink on paper
Oily residue on outsole, step on paper and apply magna powder
Gel lifter or large hinge lifters

Question 13

What are the methods for creating 3D test impressions?

Answer 13

BioFoam (preferred method)
Sculpting putty (eg. Play-Doh)
MikroTrack
Snow/dirt/mud