Forensic science exam 2

Forensic anthropology

Bones

Osteology

Study of bones, 206 in body

Function of bones

Structure, protect organs, muscle attachments, detoxify body

Information from skeletal remains

Age, sex, ancestry, height, trauma, body type, cause of death and PMI

Epiphysis

Growth plate found at ends of long bones, determines age in sub adults

Cranial sutures

Lines between skull bones that fuse with age, estimate age

Sexual dimorphism

Male: larger and robust
Female: smooth and small

Subpubic angle

Narrow in males, wide in females

Acetabulum

Hip socket, larger in males

Skull sex differences 

• Males: more robust, sloping forehead, pronounced brow ridges, rectangular chin.

• Females: smoother bones, vertical forehead, rounded skull, smaller jaw

Ancestry determination

European: long narrow nasal, oval eyes, triangle palate
African: wide nasal, square orbits, rectangle palate
Asian: rounded nasal, rounded orbits, parabolic palate

Shovel shaped incisors

Front teeth with scooped backs, asian and native american

Carabellis cusp

Small extra cusp on upper first molars, european

Human stature(height) estimation

Lengths of long bones (femur, tibia, humerus, radius)

Odontology

Dental

Adult teeth

32

Deciduous teeth

baby teeth, 20

Teeth identification

Hardest substance in body, unique to person, dna in pulp

Antemortem records

Teeth xray before death

Postmortem records

dental collected after death

Burning and teeth

Last to disintegrate, survive for identification

Clyde snow

Anthropologists, wored on Josef mengele and john wayne

Josef mengele

Nazi doctor remains identified in brazil through anthropology

King richard 3 case

skeleton found in 2012, identified using radiocarbon dating, mitochondrial dna

Bill bass

Founded body farm at University of tennessee

Body farm

Study human decomposition

Dacyuloscopy

Study of fingerprints

Bertillion system

Identification system using body measurements 

Sir Francis Galton

Established individuality of fingerprints, first classification method

Juan Vucetich

Created own fingerprint classification system, first conviction using fingerprint evidence 

Edward Henry

Developed classification system, Henry classification system,

Gilbert Thompson

First known use of fingerprints in the U.S.

Henry PDeforrest

Systematic fingerprinting within New York Civil Service

Will west case

Proved bertillion system flaws, 2 men same measurements different fingerprints

FBI fingerprint system

National fingerprint database

Permanence principle

FIngerprint unchanged through life

Ridge patterns

for classification

Friction ridges

Raised portion of the skill formed by papillae under dermis, sweat pores

Minutia-lines

Arches picture

Loop picture

Whorl-Plain picture

Whorl central pocket picture

Double loop

Accidental picture

Arch pattern- 5 percent

Ridges enter from one side, rise, and exit other side

NO DELTAS AND NO CORES

Loop pattern- 60 percent

Ridges enter and exit from same side

ONE DELTA AND ONE CORE

Whorl pattern- 30 percent

At least one ridge complete

TWO DELTAS

Henry classification system

Categorize fingerprints into 1024 categories

Whorl value system

Fingers paired and assigned values based on whorls, arches and loops are 0
(16, 8, 4, 2, 1)

Courts accept 8-12 matching points

Points of similarity

Entomology

insects

Pmi

Post morterm interval by insects

Goff’s 5 stages

Fresh: death until bloating

Bloated: abdomen inflates

Decay: skin breaks, body deflates

Post decay: 20 percent or less body remains

Skeletel: bones and hair

Autolysis

breakdown of tissues by body own chemicals, releases gas

Putrefaction

Decomposition by bacteria, skin slippage

Adipocere

Wax by fat

Necrophagous Arthropods

Insects feed directly on corpse

Early physical change

Body is pale and waxy, blood settles (livor mortis)

Necrophagous species

Feeds directly on corpse like flies and bettles

Predators and parasies

Feed on necrophagous species, like burying beetles, ants, bees, and wasps

Opportunistic species

Use corpse as habitat like spiders and mites 

ORDER YOU NEED TO KNOW

Flies Larva Beetles Ants Spiders

Blow fly (calliphoridae)

Common necrophages species arrive within minutes, feed on fluids

Blow fly life cycle

Egg, larva, pupa, adult

• Instars: developmental stages

Responsible personnel

Death investigator, technician, anthropologist collect information

• Visual, temperature, insects inside the body, insects beneath body

Aerial collection

Using a net to collect flying insects, kill with ethyl acetate, preserve in ethyl alcohol

Hand collection

Maggots with forecetps, scald in boiling water, store in alcohol

Live sampling “Maggot motel”

Place live larvaw in contain, allow to DEVELOP INTO ADULTS to identify

Scene temperatures

REcord maggot mass, body surface, ground surface, and under body temperatures

Ambient temperature

Affects egg and larval development

Maggot mass temperature reaches up to

125 F

Accumulated degree hours

Thermal energy required for insect to develop into next stage, used for PMI

Crime scene insects

M lee goff

Toxicology

Poisons in body

Types toxicology

Environment, consumer, medical

Father of forensic toxicology

Mathieu orfilla

• developed chemical nature of poisons

• Arsenic detection

Marsh test

Highly sensitive test to detect arsenic

Paracellsus principle of poison

Depends on dose

Ronald clark

Killed boy with cyanide candy

Georgi markov

Poisoned with ricin under umbrella pellet

Ideal poison

No odor, no taste, is soluable, undetectable, low dose can kill, not traceable

Poison kills the

CNS- depression

Respiratory- suffocation

cardivascular-hypotension

cellular-hypoxia

LD 50 definition

Dose kills half population within 4 hours

Order of hymenoptera

Ants bees wasps

Forensic art

arts for legal

4 main art methods

Composites

age progression

facial reconstruction

superimposition techniques

Composite imagry

graphic images by combining describes facial features from witness (hand drawn)

Age progression

current facial from abducted children using technology

Facial reconstruction

After determining age, sex, ancestory, create a face

3d vs 2d construction

skull using tissue depth markers (gatliff snow method)

vs

taught at fbi academy

Facial landmarks

anatomical points on skull for tissue thickness, muscle origin

3d facial steps

Establish age and sex and ancestory

plot landmarks

mount eyes

add fatty tissue

cover with skin

Karen taylor

Forensic artist for composit sketches and 2d construction

Betty pat gatliff

forensic artists developed 3d facial recognition

Super imposition

placement of image over another. matching skull to photograph

Rehydration tattoo

store tattoos

Types of poison symptoms

Lye: burn around lips

Carbon monoxide: red lividity

cyanide: burnt alomds

Metals: dirrhea, nausea

alcohol: blind

Elements prove poisoning

Crime committed, intent, access to poison, access to victum, death by poison, homicideal

Poison type s

specific

motive: money, jealous, political