Impressions

Objective: bite marksDo Now: Do you think bite marks are class or individual evidence?

ImpressionsImpressions are created when…• one object is pressed against

another material with enough force to leave an impression or imprint of the object. 

Examples of Impressions

Bite Marks, shoeprints, tire tracks etc.

Bite MarksIndividual evidence**Investigators can analyze bite mark for the following:

Characteristics of the teeth (position, evidence of dental work, wear patterns, etc.)

Saliva or blood (DNA)When the bite occurred

http://www.youtube.com/watch?v=thfHB5e51q8

Case Study: Ted BundyComplete the case study on Ted Bundy.

Computer Generated Overlays

Closure: How did bite marks play a role in catching Bundy?

Video case study: Ted Bundy

http://www.youtube.com/watch?v=zriSw1UBqv8

Objective: bite mark lab

Do Now: What characteristics of bite marks can make them easily identifiable?

Complete the bite mark lab

Closure:What suspect was the killer in the case?

Objective: Shoe printsDo Now: Are shoe prints class or individual evidence?

Shoe PrintsInvestigators can analyze a shoe print to determine its…• Class, or the type and brand of shoe

Individual characteristics, such as wear patterns and specific damages or defects

How to obtain shoeprints?

PhotographDusting (2-D print)Casting (3-D print)

Case study: OJ and Shoeprints

http://www.youtube.com/watch?v=kz1rrpoESa0

Complete O.J. Simpson shoeprint case study

Answers to OJQuestions

1. Class because his shoes were never found

2. No matches in FBI database

3. Answers will vary (opinion)

ClosureHow did the shoeprint examiner determine the manufacturer of the shoeprint left at the scene?

Objective: Shoe PrintsDo Now: What characteristics could make shoe prints individual evidence?

Objective: shoe print lab

Complete shoe print lab