Criminalistics Midterm 1

forensic science

the application of science to law

3 components of hair

cortex, cuticle, and medulla

cuticle

outer protective layer of hair, not very unique, made of overlapping scales, useful for IDing species because you can take the pattern to compare it

cortex

the body between the two hair layers

medulla

the center of the hair

anagen phase of hair growth

initial phase may last up to 6 years, root is flame shaped, Hair is actively growing

catagen phase of hair growth

transition phase, 2-3 weeks, root is elongated

telogen phase of hair growth

phase where hair naturally fall out of skin, root is club-shaped

hair test collection

at least 25 known hairs from different parts of the head and/or public region. Comb and pull out hairs

hair color

provided by pigments produced by cells called melanocytes. The pigments are called melanin

grey hairs

The natural production of pigment slows down

dyed hair

Hair grows 1cm a month so you can date when a person dyed their hair
Naturally colored “roots” beneath a tinting job is a way of identifying the owner of the hair

straight hair

circular diameter

wavy hair

oval cross section

curly hair

flat oval cross section

medulla index

Diameter of medulla divided by diameter of the hair
humans MI < ⅓

fibers

A class of materials that are longer than it is wide

primary transfer

the fiber was transferred from a fabric onto the victim's clothing

secondary transfer

occurs when already transferred fibers on the clothing of a suspect are from another source

fiber analysis

The shape of the material is man made and unique to the manufacturer

fiber analysis can tell___

class characteristics

color fading in a fiber

leads to increased value in fiber association

purge

fluids that leave the body after death

motor vehicle accident

note location, description of location, description of collision

drug over dose look for:

Location of drugs, medicine and alcohol, location of paraphernalia type

gunshot and stabbing note:

description of weapon, location relative to victim, ownership, place kept normally, disposition of weapon (casings)

suicide look for:

note, weapon, device, drugs, poison

female suicides

tend to avoid the face
attempt 2x more than men

male suicides

less attempts than women, but tend to be more successful in their attempts

why are graphic crime scene pictures not allowed in court?

because graphic pictures often lead to a conviction no matter the circumstance

SIDS

dont know why the child is dead, Sudden Infant Death Syndrome

epidermis

outer layer of skin

dermis

inner layer of skin

dermal papillae

layer between epidermis and dermis

papillary pattern

determines the form and pattern of the friction ridges on the skin surface

Friction ridges are found on the skin of:

palms of hands, palmar aspect of fingers, soles of feet, solar aspect of toe

If a fingerprint touches a surface___

perspiration and oil from the body parts are transferred onto the surface leaving the print

Minutiae

ridge characteristics, what makes the print unique

when friction ridge patterns develop

in utero and remains unchanged throughout your whole life

removing fingerprints

John Dillinger tried but was unsuccessful
have to remove 1-2mm of skin to really do it, but tissue scarring tends to make a person even more distinguishable

loop finger pattern

whorls finger pattern

Must have two deltas

arches finger pattern

go into plain or tented, ridges enter from one side of the print and exit on the opposite

fingerprint classification

the henry system

AFIS

fingerprint system

latent fingerprint

hidden or invisible, require enhancement to make visible with powders and chemicals

patent fingerprint

visible to the naked eye, less common, made by fingers coated in a foreign substance (blood, grease, ink etc)

plastic fingerprint

3D print

drugs

are substances of natural or synthetic origin which can alter the emotional state, perception, body fucntion, or behavior of an organism

somatic pain

pain that is originated in muscle and bone, toothache, headache, arthritic, sprains

visceral pain

pain that is originated in non-skeletal parts of the body: gastric pain, intestinal craps,etc. It is relieved only by opioid analgesics

hallucinogenics

alteration in normal thought, perception, and moods. Can haave a very diverse affect

CNS depressants

alcohol, heroin, methadone, etc all work different on the body and are unique

tolerance

a state in which an organism no longer responds to a drug

addiction

a state in which an organism engages in a compulsive behavior

dependance

a state in which an organism functions normally only in the presence of a drug

hair drug test

will show years of drug use

blood drug test

will show days or hours from drug use

alcohol metabolism

90% of alcohol is metabolized in the liver

one half ounce of alcohol take ___ to get out of system

1 hour

food and alcohol

The more carbs you eat, the slower the alcohol goes through

henry's law

when a volatile chemical is dissolved in blood, how the breathalizer measures alcohol levels through breath, a noninvasive test

nicotine

Ingestion results in immediate KICK because it causes a discharge of epinephrine from the adrenal cortex

smoking calcification

not reversible and can cause death

anabolic steroids

induce weight gain and increase muscle mass and contain testosterone

effects of steroids on immune system

Reduce the activity of immune system by affecting the function of white blood cells

ritalin

methylphenidate is a mild stimulant to the central nervous system

ritalin uses

Used to treat ADD, ADHD, and nacrolepsy
Can be used for lifestyle reasons like attention and focus

inhalants

Breathable chemical vapors that produce mind altering effects

Duquenois Levine test

field test for marijuana, turns purple

coke

blocks pain sensation and stimulates the CNS

freebase cocaine

is cocaine without its water soluble component or base
Makes it smokable, but it is very dangerous because it can blow up

crack

less pure than freebase but safer than freebase

what is crack made of

2 parts cocaine and one part baking soda with 20 mL water
The solution is heated til precipitation stops then precipitate is filtered and retained then washed

why does crack stick to money

Is a very stable chemical and adheres closely to the ink in paper currency

crack and pregnancy

draws blood away from the fetus

expert witness

the only witness in a court case that is allowed to give opinion on their specialty

coroner

an elected official, in charge of department, hire people to do the work

medical examiner

appointed by the coroner, has to pass a test

toxicology lab

what is in your body, what chemicals can they find

controlled substances lab

drugs, residues, powders, etc - and the composition and amount of it

trace lab

tiny pieces of evidence and using it to match it to a source

serology lab

blood and its owner

odontology

uses teeth and bite marks to establish a pattern

Neuropathology

the brain

manner of death

natural, hommicide, suicide, accident, pending, and undetermined

locard's

Whenever there is contact between two objects, they will leave or pick up debris from the other object

opium

Dried seedpods of poppies

heroin

more potent than morphine, it is boiled morphine

heroin on the scene

stamp bag (what the dealers have), spoons, etc

methadone

now used for the treatment of herion addiction but can be dangerous

narcan

used for overdoses and can completely inhibit the analgesic properties of opiates

Ecstasy

Synthetic psychoactive drug with both stimulant and hallucinogenic properties

LSD

Manufactured from lysergic acid which is found in ergot, a fungus on rye and other grains

ketamine

Is a PCP derivative

ketamine "k-hole"

Dreamy feeling; floating outside the body
Trance-like state
Sometimes described as a near death experience

meth

made from Sudafed

Rohypnol

Short-term treatment of insomnia
10x more potent than valium