Impression Evidence

I'm Impressed

100

Defined as objects or materials that have retained the characteristics of other objects through direct contact.

Impression Evidence

200

Which one is not an example of impression evidence?

A. striation marks on a bullet

B. shoe prints

C. DNA left at the crime scene

D. tire tracks

E. teeth marks

F. tool marks

C. DNA left at the crime scene

300

What are the three types of impressions?

Patent, latent, plastic

400

visible, two-dimensional (leaves a trail)

patent impressions

500

are hidden to the eye and require special techniques to be seen

latent impressions

What gives you that impression?

100

What type of evidence are shoe impression matches typically?

Typically class evidence:
-May not be enough to prosecute a suspect yet

Bonus!!!  (worth 200 extra points)  Can they ever be individual evidence?  If so, how?

200

What must a Forensic Technician ALWAYS do before casting or dusting an impression?

Take pictures and/or videos

300

Ridges and grooves that channel water away and provide traction are called:

tire tread

400

The unique design of a tire's surface is known as:

tread pattern

500

What type of evidence are bite marks considered?

Individual Evidence 

Bonus points!! (200 extra points) what types of things make bite marks individual?

I'm tired...

100

oils used to keep tires soft and pliable can cause:

Latent Tread Patterns

200

Impressions made after tire runs through a fluid material make these type of impressions:

Patent tread patterns

300

Three-dimensional impressions left in soft surfaces such as mud, snow, lawns are what type of impressions?

Plastic tread patterns

400

Is the black marks left by a tire that is sliding and NOT free to rotate.

skid marks

500

Distance (mm) between center of front axle and
center of rear axle

wheelbase length

Bite me!

100

How many adult teeth are there? 

32 adult teeth

200

The pattern made by a particular set of teeth is known as:

dentition pattern

300

What types of things from a person's mouth are analyzed during a crime scene investigation? (Name at least 2)

1.) Characteristics of the teeth: dental chippings, surface indentations, distances between teeth, individual tooth dimensions, alignment of teeth, angle of the mouth arch, presence or absence of teeth
2.) Type of bite mark (human or animal)
3.) Color of area to estimate how long ago the bite occurred (old recent bite)
4.) Swab for body fluids for DNA tests 

400

What types of things does a forensic odontologist do? (name 2)

The investigation consists of recognizing, documenting, collecting, and analyzing evidence
-Take photographs of bite marks using a reference tool
- Making measurements with a ruler
-Used to identify remains & used in profiling and identifying a suspect from unique bite patterns or bite marks left at the scene of the crime
-76 points of comparison  

500

How does one take a bite impression from a suspect?

1.) Choose the proper material for the bite registration (wax or high durometer polyvinyl siloxane materials)
2.) Take impression for top and bottom set of teeth (make sure the suspect bites on too material long enough to make an efficient dentition pattern)
3.) Document evidence

Quit tooling around

100

What type of evidence are tool markings?

Circumstantial Evidence

Bonus Question!!  (200 points) Why is it circumstantial?

 

200

What types of tools commonly leave impression marks at a crime scene? (name 3)

-Knives
-Crowbars
-Pliers
-Lock picks
-Screwdrivers
-Hammers
-Explosives
-Ceramic spark plugs

300

Result when a tool is pressed against a softer surface
-Tools usually leave distinctive marks
-The hardness of a tool influences the resulting marks left in the softer object

What are these marks known as? 

Indentation marks

400

Made when surfaces slide across one another
-An object's surface can be ground or worn away by a tool
-The harder object causes abrasions on the softer surface
-Indentation and abrasion marks sometimes occur at the same time 

What are these types of markes called?

abrasion marks

500

A device used to analyze side-by-side specimens for comparison purposes is called?

-Gives a closer look at the minute details found on tools (the wear and tear patterns that make a specific tool unique)

comparison microscope