Week 4 - Positive Identification

Question 1

DNA

Answer 1

most conclusive way to identify
unique
need comparison DNA - from parents or siblings

Question 2

types of dna

Answer 2

nuclear - almost all cells, from both parents
mitochondrial - from mother

Question 3

problem with dna

Answer 3

parents who have two children that are missing - cannot differentiate between them
only way is if the child had children themselves

Question 4

sources of dna - live person

Answer 4

nuclear - any nucleated cells - white blood cells, buccal smear, hair follicle
mtDNA - all above and hair shaft

bone marrow transplant - bloods dna will be different

Question 5

sources of DNA - dead person

Answer 5

fresh body - blood, tissue, hair root
decomposed or skeletonized - bone marrow, teeth (dentine under enamel)
mtDNA - hair shafts

Question 6

DNA comparison

Answer 6

unknown body gives DNA profile
compare DNA from body with premorten record of tentative ID person

Question 7

DNA databank

Answer 7

certain offenders - rape, murder
finger prick or buccal swab
DNA taken in investigation not used in bank - second sample taken after - investigation samples destroyed (fingerprints not unless asked)

Question 8

Other premortem dna

Answer 8

most women have DNA on record - pap smears

Question 9

positive ID

Answer 9

can only be one person
done after tentative ID to confirm

Question 10

methods of positive ID

Answer 10

Visual identification, fingerprints, dental records, x-rays, medical x-rays, dna, video superimposition, circumstantial

Question 11

visual identification

Answer 11

most common, least scientific
family and friends
only used with fresh bodies unless there is a specific feature

Question 12

fingerprints

Answer 12

old technique
unique
environmentally determined in utero

Question 13

fingerprints at scene

Answer 13

latent prints
individualization - its your fingerprint
identification - its A fingerprint

Question 14

three principles of fingerprints

Answer 14

individual characteristics are unique
unchanged throughout life
ridge patterns can be classified

Question 15

what are prints made from

Answer 15

oils and sweat on skin

Question 16

fingerprint individualization

Answer 16

examination of minutiae ridge characteristics - 150 per print
suspect print may be partial
no specific number of characteristics needed
officer making final say is subjective

Question 17

levels of detail

Answer 17

pattern - whorl, arch, loop (classification)
minutiae - fine lines on print used for comparison
sweat pores within minutiae

quality depends on - surface, sweat, recovery time, technique used

Question 18

problems with fingerprints

Answer 18

must have premortem record
can get prints from home - but difficult

Question 19

decomposing remains and prints

Answer 19

if skin comes off - wear as glove
fingers can be rehydrated

Question 20

dental records and x-rays

Answer 20

considered unique
differences in wear, rotation, root shape, fillings, extractions
used as signature in old days

Question 21

dental evidence

Answer 21

compare premortum with postmortum record
may not be accurate because teeth can fall out..
teeth preserve well

Question 22

problems with dental evidence

Answer 22

need premortum records
no centralized database
dentist dont keep records forever

Question 23

medical x-rays

Answer 23

broken bones, fracture records, healing patterns

implanted devices - serial numbers

sinus shape is unique

Question 24

medical records

Answer 24

written details, height, weight, surgeries, scars

Question 25

video superimposition

Answer 25

match photo of tentative ID to skull done by anthropologists angle must be identical easier to eliminate than ID

Question 26

circumstantial

Answer 26

may be only method available if a male, age 70, 150cm tall found dead in home, and apartment is owned by someone of this description, its likely him

Question 27

circumstantial ID and population

Answer 27

if 4 men shared the house - different closed population - one child on plane, plane crash, child bones found white man in africa in 1800s

Question 28

ID of children

Answer 28

difficult little or no dental work, x-rays small bones - not yet ossified easily scattered and lost sex - not until puberty, age - range, height - grow in spurts

Question 29

medical cause of death

Answer 29

trauma, disease, or event that resulted in death physiological process stabbed - blood loss strangled - asphyxiation

Question 30

mode of death

Answer 30

instrument used knife, rope

Question 31

ways to discover cause of death

Answer 31

autopsy, history of death, witness statements, medical records, scene

Question 32

clinical/hospital autopsy

Answer 32

confirms diagnoses, presence and extent of disease, medical conditions, did treatment work

Question 33

forensic autopsy

Answer 33

cause of death, manner of death

Question 34

three parts of autopsy

Answer 34

external exam internal exam toxicology

Question 35

external autopsy

Answer 35

overview of body, clothing, biological profile, under fingernails, classify injuries if they match clothes, type of injury

Question 36

internal autopsy

Answer 36

examine organs digestive tract - medication microscopic examination

Question 37

toxicology

Answer 37

blood, urine, bile, stomach contents blood - several areas due to postmortem redistribution of drugs

Question 38

wound interpretation

Answer 38

description - soft or hard tissue measure shape - of weapon type size, depth, hilt mark

Question 39

incised trauma

Answer 39

sharp force stab - deeper cut - longer

Question 40

blunt force trauma

Answer 40

contusion - bruise laceration - open wound, broken skin, tissue bridges non sharp - bat

Question 41

wound details

Answer 41

angle - weapon path defence wounds same weapon can have different wounds

Question 42

manner of death

Answer 42

homicide, suicide, accidental, natural, undetermined

Question 43

wound characteristics and manner of death

Answer 43

accident - mode near suicide - weapon to hand location of wounds - can victim reach

Question 44

knife - suicide vs homicide

Answer 44

suicide - hesitation marks, single fatal wound, wounds reachable homicide - many fatal wounds, out of reach, defence wounds

Question 45

psychology of attack

Answer 45

frenzied, tentative, height of perp, position (awake or asleep), strength (wound severity)

Question 46

other specialists involved

Answer 46

forensic anthropologist - bone trauma, exit/entry wounds firearm specialist - match marks to weapon

Question 47

where did they die?

Answer 47

moved - homicide to get rid of body, tampering with a body, compassion to disguise dignity

Question 48

What is the difference between a coroner and a medical examiner?

Answer 48

Coroners can be elected officials without medical training, whereas medical examiners are physicians and board-certified forensic pathologists.

Question 49

What is the primary role of a forensic pathologist?

Answer 49

To investigate suspicious deaths by determining the cause, manner, and time of death. conduct autopsies work in me or coroner office

Question 50

What is involved in a scene investigation by a forensic pathologist?

Answer 50

Documenting and photographing the scene, identifying injuries, collecting evidence, and making a preliminary reconstruction of events based on blood splatter, weapon recovery, and movements.

Question 51

What signs may indicate poisoning?

Answer 51

Cherry-red discoloration for carbon monoxide poisoning, pink skin for cyanide, and corrosion around lips for acid ingestion.

Question 52

What are the types of asphyxia?

Answer 52

Carbon monoxide poisoning, hanging, strangulation, and smothering.

Question 53

How can the range of fire be determined in a gunshot wound?

Answer 53

By analyzing powder residue and the appearance of the wound.

Question 54

How can drugs contribute to death?

Answer 54

Drugs can cause death directly or impair judgment, leading to accidents or violence.

Question 55

What part of the skin determines fingerprint patterns?

Answer 55

The shape of the dermal papillae at the boundary between the epidermis and dermis.

Question 56

What defines a loop fingerprint pattern?

Answer 56

ridge enters from one size, exit from same size one delta, core unlar - pinkie radial -thumb

Question 57

What characterizes a whorl fingerprint pattern?

Answer 57

Whorls are circular or spiral ridge patterns with two deltas. plain, central pocket, double loop, accidental

Question 58

What defines an arch fingerprint pattern?

Answer 58

Arches lack type lines, deltas, or cores, and ridges enter from one side and exit from the other. plain, tented

Question 59

What does the ACE-V process stand for in fingerprint analysis?

Answer 59

Analysis: Identify distortions and determine if the fingerprint is usable for comparison. Comparison: Compare fingerprint to a known print at three levels: General ridge flow. Ridge characteristics (minutiae). Finer details (ridge pores, creases, scars). Evaluation: Conclude identification (same source), exclusion (different source), or inconclusive. Verification: A second examiner independently verifies the result.

Question 60

primary classification in prints

Answer 60

each finger is paired whorls given a value for each pair, starting at 16 then half 1 is added to numerator and denominator

Question 61

What is AFIS?

Answer 61

Automated Fingerprint Identification System AFIS scans and converts fingerprints into digital data focusing on minutiae, and compares them to database entries. Human experts make the final verification.

Question 62

What is Livescan?

Answer 62

An inkless, digital system that captures fingerprints and palm prints and immediately enters them into AFIS.

Question 63

What are the three types of fingerprints?

Answer 63

Visible prints: Made when a surface is touched after contact with colored material (e.g., blood, paint). Plastic prints: Ridge impressions left on soft materials (e.g., putty, wax). Latent prints: Invisible to the naked eye, formed by perspiration or oils on the ridges.

Question 64

How are latent fingerprints located on different surfaces?

Answer 64

Hard and non-absorbent surfaces (glass, tile): Developed with powder or superglue. Soft and porous surfaces (paper, cloth): Developed using chemicals.

Question 65

What are common techniques for detecting latent fingerprints?

Answer 65

Powder: Aluminum for dark surfaces, carbon for light surfaces. Superglue fuming: Forms a visible white print. Chemical methods: Ninhydrin reacts with amino acids. RUVIS: Uses ultraviolet light to detect prints.

Question 66

What is digital imaging in fingerprint enhancement?

Answer 66

Converts fingerprints into digital files for analysis. Techniques like contrast adjustment and spatial filtering help make prints clearer.

Question 67

describe iodine fuming, ninhydrin, physical developer, superglue fuming

Answer 67

Iodine sublimates into vapor when heated, interacting with oils or moisture in a latent print. Ninhydrin reacts with amino acids in perspiration, turning the print purple-blue. physical developer - A silver nitrate-based chemical used to develop prints on porous surfaces, especially ones that have been wet. Superglue vapor interacts with fingerprint residue to produce a white print. It is used on nonporous surfaces and is ideal for enclosed spaces.