Trace Evidence

Question 1

Trace vs transfer evidence

Answer 1

Trace evidence is not always noticeable; transfer is the result of contact

Question 2

Evidence can be searched for hairs using what?

Answer 2

A stereomicroscope

Question 3

Picking

Answer 3

Observing and removing individual hairs

Question 4

Taping

Answer 4

Using the adhesive side of tape to pick up hairs

Question 5

Vacuuming

Answer 5

Using a suction device with a fine screen to capture hairs

Question 6

Known hair samples are collected by

Answer 6

Combing and pulling

Question 7

Hair

Answer 7

Filament growth from the skin

Comprised of keratin, proteins, amino acids and melanin

Question 8

Cuticle

Answer 8

Outermost later of the hair shaft

Question 9

Cortex

Answer 9

Second layer of the hair shaft

Question 10

Medulla

Answer 10

Core of the hair shaft

Question 11

Anagen phase

Answer 11

Active growth phase of hair

Question 12

Catagen phase

Answer 12

Hair stops growing

Question 13

Telogen phase

Answer 13

Hair is naturally shed

Question 14

Protein fibers

Answer 14

Composed of polymers and amino acids; wool and silk

Question 15

Cellulosic fibers

Answer 15

Formed from glucose; cotton and linen

Question 16

Mineral fibers

Answer 16

Composed of silica; asbestos

Question 17

Natural fibers

Answer 17

Protein, cellulosic, mineral

Question 18

Manufactured fibers

Answer 18

Synthetic, Inorganic, Regenerated

Question 19

Raman Spectroscopy

Answer 19

Measures vibrations that bonds undergo within molecules

Question 20

How should paint evidence be collected?

Answer 20

Either by collecting the entire item with paint or removing the paint from the item

Question 21

Organic coatings of paint

Answer 21

Electrocoat, primer, basecoat, clearcoat

Question 22

Electrocoat

Answer 22

First layer; color ranges from black to grey

Question 23

Primer surface

Answer 23

Second layer; lots of color pigment

Question 24

Basecoat

Answer 24

Becomes the visual color of the automobile

Question 25

Methods of chemical analysis of paint

Answer 25

FTIR and pyrolysis gas chromatography

Question 26

FTIR

Answer 26

identifies paint materials through measuring absorption of infrared radiation

Question 27

Major types of glass

Answer 27

Flat, container, fibers

Question 28

Types of cracks

Answer 28

Radial Concentric Intersecting

Question 29

Radial cracks

Answer 29

Start at the area of impact and move outwards

Question 30

Concentric cracks

Answer 30

Occur on side of glass where force was applied; looks like a circle around impact zone

Question 31

Wallner lines

Answer 31

Arc-shaped marks that help determine which side of the glass force was applied on

Question 32

Becke line

Answer 32

Bright halo at the edge of an object

Question 33

Match point in glass

Answer 33

Line disappears

Question 34

Cortical Fusi

Answer 34

Small air pockets trapped within the hair body

Question 35

Follicular tag

Answer 35

Tissue and living cells forming the proximal tip of a hair strand

Question 36

Human hair has a ____ cuticle

Answer 36

imbricate

Question 37

Human hair has a ____ medulla

Answer 37

unstructured

Question 38

Human hair cortex makes up _____ of the width

Answer 38

65%

Question 39

Hairs in which growth stage are most desirable to be collected at a crime scene?

Answer 39

Anagen because they have a follicular tag

Question 40

The light microscope is good for ______

Answer 40

magnification

Question 41

The right tool for anisotropy and birefrigence is the _____

Answer 41

polarizing light microscope

Question 42

The peaks in UV and IR spectra are caused by

Answer 42

Different types of chemical bonds in the material

Question 43

Sherwin Williams makes water-based latex paint in a number of different finishes (levels of shininess) matte, satin, semi-gloss, and glossy. If you compare two paints of the same color, but different finishes, which paint component will be chemically different?

Answer 43

the modifier

Question 44

Both Layer comparison and physical match can be performed with which type(s) of paint evidence

Answer 44

chips

Question 45

I knocked over a shelf and broke a clear glass unicorn and a clear glass mason jar. Both have nearly identical density, so I will need to use their refractive indices to determin which bits of glass go with which item

Answer 45

Polarizing Light Microscope Hot stage refractometer Becké line analysis

Question 46

When using the hot oil method, what do we compare between our suspect and our known?

Answer 46

The temperature at which the outline of the glass disappears.