Chapter 14 Trace Evidence Ii

Front 1

The _ component of paint is commonly a mixture of inorganic and organic compounds and imparts color and hiding (or opacity).

Back 1

pigment

Front 2

The support within paint is provided by the _ component, which is a polymeric substance.

Back 2

binder

Front 3

True/False: Layers of paint are applied in the order of primer first, then surfacer, basecoat, and finally clearcoat.

Back 3

True

Front 4

The questioned and known paint specimens collected from a scene should be compared side by side under a __ microscope, which shows a three dimensional image, to look at color, surface texture and color layer sequence.

Back 4

stereoscopic

Front 5

In forensic comparison the most important physical property of paint is _.

Back 5

layer structure

Front 6

Paint can be individualized to a single source only when they have a sufficiently detailed _.

Back 6

layer structure

Front 7

True/False: Pyrolysis gas chroma. is a particularly valuable technique for characterizing paint's binder.

Back 7

True

Front 8

Pyrolysis gas chroma. yields a _ to reflect the chemical make-up of the binder.

Back 8

pyrogam

Front 9

The Royal Canadian Mounted Police's database is called _, allows an analyst to obtain information about a cars make, model and year.

Back 9

PDQ/Paint Database Query

Front 10

True/False: Paint samples removed for examination must always include all of the paint layers.

Back 10

True

Front 11

_ is defined as a hard, brittle, amorphous substance composed of sand (specifically, silicon oxides) mixed with various metal oxides.

Back 11

glass

Front 12

True/False: Automobile paint headlights and heat-resistant glass, such as Pyrex, are manufactured with lime oxide added to oxide mix.

Back 12

False

Front 13

_ glass fragments into small squares, or "dices," with little splintering when broken.

Back 13

tempered

Front 14

_ glass gains added strength from a layer of plastic inserted into two pieces of ordinary window glass; it is used in car windsheilds.

Back 14

laminated

Front 15

Broken glass that can be physically pieced back together has _ characteristics.

Back 15

individual

Front 16

The two most useful physical properties of glass for forensic comparisons are _ & _.

Back 16

density & refractive index

Front 17

Comparing the relative densities of glass fragments is readily accomplished by a method known as _.

Back 17

floatation

Front 18

When glass is immersed in a liquid of similar reactive index, its _ disappears and minimum contrast between glass and liquid is observed.

Back 18

Becke line

Front 19

The exact numerical density and reactive indices of glass can be correlated to their _ in order to assess the evidential value of the comparison.

Back 19

frequency of occurrence

Front 20

The fracture lines radiating outward from a crack in glass are known as _ fractures.

Back 20

radial

Front 21

Glass fracture lines that encircle the hole in the glass are known as _ fractures.

Back 21

concentric

Front 22

True/False: A crater-shaped hole in glass is wider on the side where the projectile entered the glass.

Back 22

False

Front 23

True/False: It is easy to determine from the size and shape of a hole in glass whether it was made by a bullet or some other projectile.

Back 23

False

Front 24

When glass's elastic limit is exceeded the first fractures develop into radial lines on the surface of the _ side of that of the penetrating force.

Back 24

opposite

Front 25

True/False: Stress marks on the edge of a radial crack are always perpendicular to the edge of the surface on which the impact force originated.

Back 25

False

Front 26

A fracture line from a successive impact will always _ at an existing line fracture.

Back 26

terminate

Front 27

Collected glass fragment evidence should be packaged in _ containers to avoid further breakage.

Back 27

solid

Front 28

Glass-containing shoes &/or clothing should be individually wrapped in _ and transmitted to the lab.

Back 28

paper

Front 29

True/False: Most soils have undistinguished color and texture.

Back 29

False

Front 30

Color and texture comparisons cannot be made on samples until they are all _ under identical lab conditions.

Back 30

dried

Front 31

Naturally occurring crystals commonly found in soils are _.

Back 31

minerals

Front 32

True/False: The ultimate value of soil as evidence depends on its uniqueness to the crime scene.

Back 32

True

Front 33

To develop an idea of the soil variation within the crime-scene area, standard/reference soils should be collected at various intervals within a _-yard radius of the crime scene.

Back 33

100

Front 34

True/False: Each object collected at the crime scene that contains soil evidence must be individually wrapped in plastic, with the soil intact and transmitted to the lab.

Back 34

False