2) 2D & 3D Impressions

Question 1

What four things do you need to check when locating visible impressions?

Answer 1

1) Route to scene
2) Point of entry
3) Distrubed areas
4) Point of exit

Question 2

What is the term “Path of Contamination” used to describe?

Answer 2

The route responders create to avoid disturbing evidence at a scene

Question 3

In locating & marking 2D evidence, when examining the floor of a scene, ensure the room is ________________ and hold a light source at a low (___________) angle to locate impressions.

Answer 3

Darkened

Oblique

Question 4

Damp impressions may be more receptive to fingerprint _____________.
Fingerprint _______ can be used to preserve fingerprints on glass and plastic.

Answer 4

Powders

Tape

Question 5

[2D impressions] What kind of device is usually a Pathfinder and uses a sheet of Mylar?

Answer 5

Electrostatic lifting device

Question 6

What are some advantages & disadvantages of an electrostatic lifting device?

Answer 6

Advantages: easy to use, Mylar can be reused, provides fine detail, Mylar doesn’t lose it’s static properties

Disadvantages: cost (pathfinders cost over $800)

Question 7

[2D impressions] Gel lifters consists of a __________ layer covered by a _________ ______________ and supported by a black or white rubber backing

Answer 7

Gelatin

Clear Acetate

Question 8

What are some advantages & disadvantages of gel lifters?

Answer 8

Advantages: produces fine detail, comes with clear acetate cover to preserve impression, easy to use

Disadvantages: cost approx $10 for sealed package of 2, needs to be kept in cool storage, gel can dry out over time

Question 9

[3D impressions] When photographing an impression in the snow, _______ _________ ______ or __________________ ______________ ___________ will provide good contrast as well as act as a __________ ___________.

Answer 9

Snow print was
Contrasting primer paint
Parting agent

Question 10

[3D impressions] What are 3 advantages of dental stone (compression strength of 8000 psi)?

Answer 10

Inexpensive
2 lbs per footwear impression
Robust

Question 11

______________ may be used for snowprint impressions only
Advantages: Inexpensive, requires _____________________________________________ (time consuming), 5 lbs per footwear impression, fragile but produces fine detail

Answer 11

Sulphur

Camp stove to heat and melt