forensics

latent

need to use dusting or electrostatic techniques to see it. Not visible to the naked eye.

patent

visible with the naked eye

plastic

3D imprints left in pliable materials like snow, mud, soil, etc.

MUST BE PHOTOGRAPHED IMMEDIATELY because a soft substrate can cause the print lost.to be 

cutting marks

produced along the edge of a surface as it is cut.

abrasion marks

made when surfaces slide across one another

the harder surface leaves a scratch on the softer surface

indentation marks

an impression made by a tool when it’s pressed against a softer surface

it is a negative impression of the tool

ways tools could be changed

oxidation, rust, or uneven sharpening of tools

T/F keep tool and mark separate

TRUE- never put tool back to the mark

things that make footwear unique

size of person’s foot, depth of shoe impression, gait, pressure

ways to lift latent prints

chemical, electrostatic (use charge to lift print), and dust

tire groove

valley, down

tire rib

up/risen area

track width

width between front or rear tires.

middle of each tire

wheel base

middle of front to middle of back tire

turning diameter

each car has a different diameter

skid marks

brakes suddenly and locked wheels

calculate velocity from skid marks

yaw marks

produced when a vehicle travels in a curved path faster than the vehicle could handle. skids sideways.

tire and road surface melt from extreme temps

tire scrubs

damaged or overloaded tires after impact

usually curved, determine area of impact

if you cut things where will you see it

on the bone

why do you take a picture of shoe impressions

the print could get messed up

what do you take a picture of the shoe mark with

a ruler or something you can scale with

tool marks are what type of evidence and why

circumstantial because having a tool consistent with the one used during the crime doesn't establish the suspects presence at the time of the crime

is shoe size an indication of sex and height

there is only a general correlation between shoe size and height but it is not 100%

bitemark evidence

it is inaccurate yet they keep using it because its been used in the past. Science ahs proven how bite marks are not reliable due to many factors affecting the pattern.

deductive reasoning importance

general→specific. Helps decrease potential suspects. Janice is an aerobics instructor, whose classes start at 7:30pm. the crime was thought to happen 7:45pm Janice never missed a practice so she couldn't have been the murderer