1Physical property
describes the behavior of a substance without reference to any other substance EX: human or animal hair?, natural or synthetic fibers?
2Chemical property
Behavior of a substance when it reacts or combines with another subtance EX: color change of a drug to a chemical
3Basic units of length, mass, and volume
length - meters
mass - grams
volume - liters
4Element
matter that cannot be broken down into simpler substances by chemical means
5Periodic table
chart that lists all the elements
6Atom
smallest unit of an element
7Compound
substances that are made of two or more elements
8Solids
definite shape and volume because molecules are so compact
9Liquids
definite volume, no definite shape because attractice forces are weaker
10Gases
no definite shape, no definite ovlume because attractive forces are weak enough for the molecules to move freely
11Sublimation
change of state from solid to gas directly without going into liquid state
12How is sublimation important in forensic science?
its used for lifitng finger prints with iodine crystals
13Dispersion
Separating light into its component colors
14Refraction
beinding of light wave due to change in its velocity
15What is the basis for the spectrophotometer in forensics?
certain things absorb certain wavelengths of light and relect others, used to analyze drugs
16Freezing point of water
O Celsius, 32 Fahrenheit
17Boiling point of water
100 celsius, 212 fahrenheit
18Density
mass per unit volume, D = M/V
19What is refractive index
velocity of light in a vacuum
20Intensive property
substance remaining the same regardless of size EX: refractive index, density
21How is the electromagnetic spectrum used in forensic science?
it's used in identification and classification of chemicals
22Becke line
Bright halo observed near border of particle immersed in liquid of diffferent refractive index
23How is the becke line used to determine refractive index of a glass sample?
Halo inside glass = glass has higher RI
No becke line = same RI
Beck line outside glass = liquid has higher RI
24Why is glass important in forensics?
it's important due to its abundance and durability
25Why is glass considered class evidence?
it's mass produced and because the shards found at the crime scene are often too small to put together
26How is glass modified to give us different types of glass?
You can add lead to make it more dense, borosilicate to make it heat resistant, and iron oxide to give it differnet colors
27Tempered glass
made to be strong but doesn't shatter when it breaks, side and rear windows
28Laminated glass
A plastic sheet is bonded in between two glass plates, in the windshield
29Only way to individualize class evidence
to put all of the shattered pieces of glass together
30Radial fractures
crack starts at force of impact and extends out, formed on opposite side of impact
31Concentric fractures
forms a circle around point of impact, formed on same side of impact
32High speed objects produce what kind of fractures? Give 1 example of high speed object.
produces more and tighter circles, Bullet
33Slower speed objects produce what kind of fractures? Give 1 example of slower speed object.
produces fewer, more widely spaced circles, hammer strikes/ rocks
343R Rule
Radial cracks form right angles on the reverse side of the force
35How is the 3R rule applied to the analysis of glass fractures?
It can tell which side the force was applied
36How can an investigator determine the order in which several successive fractures of a glass occurred?
Fracture lines always terminate at an existing line of fracture
37If laminated glass is found at scene, investigator should
look for cars that have broken windshields
38Lingberg case
Joselyn baby kidnapped
wood from ladder was from inside a building bc it wasnt weathered (possibly attic)
gold certificates from tin can came from german friend bc he owed him money but there was no record stating that he owed Hauphman money
problem with evidence - the reporter put the number in the closet (claimed to have written it), eye witness was legally blind, police interrogated witnesses (bias)
author claimed that Dwight Morrow Jr. (brother in law of lindberg)