Physical Evidence Compar

Question 1

Define Physical Match

Answer 1

Physical match occurs when the examination of the physical characteristics of two or more pieces of evidence reveals they are fragments from what was previously one continuous object, and are therefore of a common origin.

Question 2

What are the 2 physical evidence comparison principles?

Answer 2

Principle of uniqueness

Principle of identification

Question 3

What is the principle of uniqueness

Answer 3

No 2 things

• happen by chance ever happen in exactly the same way
• are ever constructed or manufactured in exactly the same way
• ever wear in exactly the same way
• ever break in exactly the same way

Question 4

What is the principle of identification ?

Answer 4

If proper methodology is followed and there exists sufficient clarity in an object/impression, it may be identified as originating from a particular source.

Question 5

What is the physical evidence comparison methodology?

Answer 5

ACE-V

Question 6

What are the 2 types of characteristics to look at in conducting an analysis in physical evidence comparison?

Answer 6

Class characteristics - similar to level 1 detail. Happens during manufacturing. CAN’T be used to identify, but can be used to exclude

Randomly acquired characteristics - similar to level 1 and 2 detail. Can be used to identify or exclude.

Question 7

What are examples of class characteristics ?

Answer 7

Colour, shape, size, style, model, pattern, diameter, thickness, number of threads/wires/holes, composition, texture etc

Question 8

What are randomly acquired characteristics?

Answer 8

Something that is randomly added to or taken away from the original structure of the object that causes or contributes to making the object unique from all other objects sharing the same class characteristics.

Question 9

What are the 2 basic rules to follow when doing physical comparisons?

Answer 9

Compare unknown to known - class then RAC

Compare like to like

Question 10

What are the 4 possible options in the evaluation phase?

Answer 10

Inconclusive
Exclusion
Similar to
Identification

Question 11

What does similar to mean?

Answer 11

The pieces could have a common origin. There is correspondence of class characteristics but insufficient RACs are present for a positive identification