Forensics Junior Midterm

Antigen

any foreign substance that enters the body

Four blood types for humans

O, A, B, AB

Blood type is the universal donor

O

Blood type is universal recipient

AB

Type O can receive

O

Type A can receive

O, A

Type B can receive

O, B

Type AB can receive

O, A, B, AB

An Rh- mother carrires and births an Rh+ baby. What are life-threatening problems for the baby?

mom creates antibodies to attack baby

Rhogam shot

antibody attacks moms antibodies made for Rh+ baby

Crime Scene Investigation Unit

collect and preserve physical evidence to be processed in crime lab

Locard’s Exchange Principle

two objects come into contact with another leading to an exchange in material

Ex of Locard’s Exchange Pricniple

ex: mugger robs woman who fights back. The piece of woman’s hair is on mugger’s jacket

Ex of Biology unit

ex: hair

Ex of toxicology unit

ex: organ

ex of physical science unit

ex: paintFo

forensic science

application of science into criminal and civil law enforced by police through criminal justice system

Why is it important to secure and isolate the crime scene by restricting who can go into the crime scene?

Evidence can be compromised or lost

List four important descriptors on a rough sketch

Compass

Object labeled (letter/number)

Accurate sizing

Legend

Reason notes are taken at crime scene

details refresh memories

List three pieces of evidence looked for in an autopsy

Scrapping under fingernail

Cross transfer (fibers/hair)

Tissue/organ (toxicology)

What changes can happen to evidence

contamination, broken, scratched, bent, evoporation, improper packaging

List six pieces of evidence used to package evidence

forceps, gloves, manila envelope, sealable plastic bag, metal box, paper bag

Bodily fluids are stored in air-tight containers

Mold/mildew

Chain of custody and why is it important

Every person who handles and examines evidence is accounted for and signed off so evidence isnt tampered

List three examples of physical evidence of biological materials

fibers, hair, organs and bodily fluids

List three examples of physical evidence of impressions

tire marks, bite marks, shoe print

List three examples of physical evidence of manufactured items

Paint, plastic bag, vehicle light

Individual physical evidence

Properties of evidence that link it to a single source

Examples of individual physical evidence

handwriting and fingerprint

class physical evidence

Properties of evidence that can be associated with a group

examples of class physical evidence

blood types, brand of clothing

Weakness of class physical evidence

group category is large which narrows suspect little so many pieces and makes are created

First principle of fingerprinting

Fingerprint is an individual characteristic (no two fingers posses identical ridge characteristics)

Second principle of fingerprinting

Fingerprint remains unchanged during a persons life

Reason for ridges on the finger

grip securely and resits slippage

latent fingerprint

Fingerprint is made out of deposits of oil and perspiration (cannot be seen with naked eye)

Third principle of fingerprinting

Fingerprint have general ridge pattern that is systematically classified

Describe of loop pattern (enter and exits)

enters center finger, curves around and exits out same side as entered

Plain whorl

bullseye, closed pattern, can be circular, oval, or spiral

central pocket

closed pattern can be circular ovarl or sporal with a bigger space or pocket in center

Arch pattern enters and exits

enters ones side and exits the other side

plain arch

raises smoothly in the center of print

tented arch

makes a sharp spike or uplifts in the center of print

element

simplest form of matter (cannot be broken down chemically)

compound

pure substance, two or more elements

sublimtation

change in state from solid directly to gas

wavelength

distance between a point on a wave to same point on the next

frequency

number of waves that pass a given point at a given time

what does temperature measure

heat (kinetic energy)

freezing point in celsius

0

freezing point in fahrenheit

32

boiling point in celsius

100

boiling point in fahrenheit

212

mass

amount of matter an object contains

weight

force of gravity pulling down

density

mass/volume

the main ingredient of glass

sand

windows are made of ? glass

soda lime

pyrex is heat resistance because of

boron oxide

Tempered glass

stronger than ordinary window glass because stress is introduced with rapid heating and cooling (fragments into small square with little splintering)

example of tempered glass

ex: side and rear window

laminated glass

one layer of plastic between two pieces of ordinary window glass

example of laminated glass

ex: windshield in car

two physical properties used to identify glass type

density and refractive index

Becke line

bright halo observed near the border of the glass immersed in a liquid with a different refractive index

radial fracture

crack in the glass that extends outward

concentric fracture

crack in glass that forms a rough circle around the point of impact

The first shot mean there are ? stops

0

the second shot means there are ? stops

1

the third shot means there are ? stopped

2