Categorias: Todos - genetics - transcription - inheritance - alleles

por E V 10 meses atrás

99

Death investigation process

Genetics play a crucial role in determining the characteristics and traits of living organisms, with multiple alleles contributing to the diversity observed in nature. Mendelian genetics, based on the principles established by Gregor Mendel, explain that traits are controlled by a single locus and follow predictable inheritance patterns.

Death investigation process

Death investigation process

Forensic pathology

expert of testimony
Summoned to court under a subpoena
event has legal or civil proceedings
Diseases
disease has a heritable component
Examine all organ systems of the body
interpret contributed to or caused death
Injuries
- Blunt force - Sharp force - Firearm - Asphyxia - Environment
collection of trace evidence
evidence that link decedent with another individual
evidence that may indicate sexual activity
Forensic entomology
Succession pattern of insects
Non scientific identification
Circumstantial evidenc

documents

belonginigs

Distinctive marks
Physical attributes/profiling

congenital conditions

healed injuries

stature

sex

age

Visual identification
factors of death
microbiology

non-vaccinated

immunocompromised

Infection

toxicology

Intoxication with drugs

poisoning

Medicolegal autopsy
steps

Clinicopathologic diagnosis

Provide opinion on cause of death

Summarize findings in report

Ancillary studies

Internal examination

Look for disease/injury

Dissect organs and tissues

External examination

Trauma

Collect biologic samples

Collect physical evidence

History, Scene & Circumstances

Medical and social history

clothing

body position

Environment

Scientific identification
Medical hardware

Medical device with unique serial number

Radiology

Comparison of distinctive markings or characteristics

Deoxyribonucleic acid

mitochondrial DNA comparison

Nuclear DNA

Odontology

distinctive configuration of bony structures of jaw

teeth roots and nearby sinuses

Comparison of dental fillings

Fingerprint comparison

based on finger ridge patterns

Medicolegal Systems
Coroner certifies manner of death
In Canada and USA, Coroner may be physician
medical examiner
Certifies cause and manner of death
Performs death investigation
Qualified pathologist; training in death investigation/forensic pathology
Objectives of death investigation
6. Recognize practices / conditions that could have led to death
5. Manner of death: “by what means”
4. Cause of death: “how”
3. Location of death: “where”
2. Time (date) of death: “when”
1. Identification of decedent: “who”
Roles
Provide expert testimony
Document disease processes
Document injuries / Interpret
postmortem time interval and time of injury

Degree of decomposition

identification of an unknown decedent
Determine cause, mechanism, and manner of death
determines cause of death by performing autopsy
investigation of cause and manner of death by the performance of medicolegal autopsies
through genetic testing
through recommendations
information to agencies that provide benefits
plan for health policies
data for population statistics on morbidity/mortality
provide answers to living family members

Forensic anthropology

expertise
field to lab to court

- reconnaissance - search design - search - recovery - documentation - analysis - expert witness testimony

- aid the forensic pathologist - identification

Analysis

Biological profile

- age - sex biogeographical affiliation - stature - trauma/pathological conditions

mini- minimum number of individuals

Chain of custody

Document any item removed from scene

Recovery and transportation

- method matches specimen - bones

Documentation

- occurs at each step - mapping

Search methods

- line searching - walking - hands and knees - uphill/downhill - equipment

Search design

- direct or remote - terrain - time of year - hazards - search purpose - budget - available personnel

Reconnaissance

- Do not enter the scene - aerial photograph - maps contemporary - perimeter photography, video, sketches ] - intangible evidence

casework
- images from police - fire recovery - found human remains
Expert report and testimony
- reports submitted - relevant case info - all parties attending - statement of forensic significance - biological profile - analytical findings - expert interoperation of data
Taphonomy
effects of environment on bone from death to recovery
Forensic significance
material to criminal investigation/trial in court of law

- Re-evaluated throughout analysis - basis of full search - always significant until proven otherwise

Death investigation teams
- police homicide investigator - forensic pathologist - forensic odontologist - ballasts

genetics

Transcription
orcherstrated by the ribosome
process by which RNA polymerase turns genes into RNA
DNA = deoxyribonucleic acid
enzyme that synthesizes new DNA from existing DNA template
Two stranded that coil around each other to form a double helix
Galton says traits
Phenotypes grade imperceptibly from one category to the next
Mendel's law
Third law

States that recessive alleles will always be masked by dominant alleles

Second law

law of independent assortment

states that alleles segregate equally and independently
Polygenic traits
interaction of several genes
Incomplete dominance
one allele not completely dominant over other allele
Co-dominance
phenotypes produced by both alleles clearly expressed
Multiple alleles
only two allele pedigrees, whereas in nature, genes can exist in several different forms

whereas in nature, genes can exist in several different forms

Non mendelian genetics
don’t explain some patterns of genetic inheritance
one-gene equals one-phenotype

some muscular dystrophies

cystic fibrosis

Sickle cell anemia

Mendelian traits are controlled by a single locus
mendelian genetics
invisible factors ; predictably determining trait of an organism
inheritance
living things have set of characteristics/traits

inherited from parents

Injury interperation

Types of injuries
firearm

types

shotgun

machine gun

handgun

single- shot pistol

derringer

revolver

Wound pattern depends on

exit gunshot wound

external beveling

slit-like appearance

stellate

irregular

entrance gunshot wound

bones

internal beveling

circular or “punched out”

range of fire

Pathologic range of fire

Distant / Indeterminate

Intermediate

Close

Contact

distance between the firearm muzzle and tissue

type of ammunition used

type of firearm used

environment

extremities

epidural or extradural heat

white translucency of corneas

Soft tissues burn away and bones can fracture

fire

External Examination

skin

burn marks

Protrusion of abdominal contents

Longitudinal splits

Due to heat effect

Body with pugilistic attitude

Smoke inhalation

Burns and thermal injuries

Hot environment

Heat stroke

Environmental hyperthermia

heat exhaustion

Cold environment

Hypothermia

Frostbite

electricity

Lightning strike

Electrocution

Asphyxia

Chemical asphyxia

Displacement of oxygen

Cyanide

Hydrogen sulfide

Carbon monoxide

pressure

Autoerotic asphyxia

Choke holds

Hanging

Ligature strangulation

Manual strangulation

Mechanical asphyxia

Crush asphyxia

Positional asphyxia

body position compromises breathing

Traumatic asphyxia

large heavy object compressing chest

Pressure on the outside of the body

classifying

Drowning

Plastic bag asphyxia

Chemical asphyxia

External next compression

Mechanical asphyxia

Death due to cerebral asphyxia

Failure of cells to receive or use oxygen

defense wounds

injury is blunt or sharp

alive and alert at the time of injury

caused by pointed/sharp edged

Chop wound

heavy sharp object creating the wound

Incised wound

straight edges

deep wound

Stab wound

sharp edges around wound

depth of wound

during active defense from weapon

Blunt force

calculation

Force = mass x acceleration = kilogram x (meter / second2)

Force varies with mass of object

nversely varies with the duration

Abrasion

removal of superficial layer of skin

produced from

destruction of superficial layers by compression

friction against a rough surface

patterned abrasion

imprinted/stamped onto the skin

Imprint of the object

Variation of an impact abrasion

impact abrasion

Scrape/brush abrasion

Contusion

Bruise

Fracture

break in the bone

Laceration

tear in tissue

caused by

shearing

crushing force

occur when

blunt object / surface

produces

crushing

tearing

shearing

scraping

strikes with

struck with

Manner of death

undetermined
yielded insufficient evidence for any specific classification
responsible
joint investigation

rail deaths

transportation safety board

rail investigators

fire death

emergency management

fire marshal

Homicides

police

Post scene analysis
deaths investigated
specified natural
coroner jurisdiction
collect/analyze forensic evidence
Investigation power

compel law

any finding legal

delegate power

non warranty authority

extract info

seize anything

enter/inspect

warranty authority

burial

post mortem

body possession

speaking to families
warrant for post mortem
scenes to treat carefully
answer five questions

what they need

Who

DNA

prints

documents

demographics

how

medications

circumstances

medical history

by what means

where

evidence body

demographics

what

purpose

in public interest

stages
reporting
verification
post scene analysis
scene analysis
preparation
notification
public health
police services

pathologist

consultant

other agencies

forensic scientist

Canadian death investigation
coroner

forensic art

Composites
Age progression
objects/markings
Composite drawing
- witness sees suspect face - witness believe they recognize them of they saw them again - cognitive interview - unlocking memory codes
Likeness
combined with facts and details can combine to create solid investigation leads
goal for everything
Human recognition
- recall recognition context - recognition is holistic
Professional relationships
- forensic pathologists - forensic anthropologist - forensic odontologist
recreate an artistic rendering of the face

of an unidentified individual

any art that is an forensic nature

forensic biology

DNA testing
Crime scene compared to suspects
profile by itself is fairly useless
STR DNA profile
combination of alleles at reach
each marker will have two alleles
Teaching

Special case work

Audits

Cold cases

develop new techniques and validate new tech
case work
report writing

examinational testing and interpretations

make a comparison between the reference samples
case consultation with police
Serology evidence exam
non specific but indicated potential presence of biological
testing performed to look biological fluids
evidence submitted from investigators/police
justice system
scientific analyses

CSI

forensic laboratory

law enforcement

laws police training

police agencies

Human genome project
Genes are approx 5% of human DNA
Mapped entire human genome

Entomology

study of insects and other arthropods
Board Certified Forensic Entomologist
practice of medico-legal entomology
research
promote education
beetles
beetles eat larvae
blowflies
life cycle

egg

pupae

larvae

adult

Applications of forensic entomology
- Post mortem interval - Neglect - Endotoxicology - Extracting human DNA - Disposal of body - Movement of the body after death

disposal of body

Feed on tissue around a wound, destroying evidence

Larvae may move clothing to appear like a sexual assault took place

location will affect decomposition and insect colonization

larvae tissue
extracting human DNA
post mortem interval
Insects are cold blooded

develop faster at warmer temperatures

entire period after death
stages of decomposition
Chemical breakdown occurs
few morphological changes are observed
bloated

obvious odor present at this time

bloated appearance

active decay

due to the gases escaping from the body

very strong putrid odor

dry stage

insects are still present at this stage.

arcass has been reduced to bones

advanced decay

large amount of the flesh removed

odor is less obtrusive than in the previous stage

Death investigation

Autopsy
manner

circumstances surrounding death

suicide

accidental

undetermined

homicide

natural,

mechanism

asphyxia

final physiological derangement

cause of death

strangling

physiological derangement in the body

medicolegal

forensic

obscure/unnatural

sudden/suspicious

does in legal authority

clinical

hospital

extent of disease to treat descendant

treating with consent

reportable deaths
death in care

during work

prison

psychiatric hospital

long term care facility

non natural

accident

overdose

disease/sickness not treated by qualified medical expert
suddenly/unexpectedly
during/following pregnancy
medical misadventure

malpractice

misconduct

negligence

violence
objectives
public health and policy
post- mortem interval
manner of death
cause of death
identification
Purpose
assist in administration of justice
population statistics on morbidity/mortality
prevent similar deaths
provide answers to family members
Experts
medical examiner

Medical doctor

chief/deputy chief

forensic pathologist

police homicide investigator
coroner

roles

determining cause/circumstances for

unnatural deaths

unexpected deaths

unexplained deaths

access decedent medical records

determine need for further tests/investigators

order investigations or inquests

physician or “lay” person

forensic pathologist

Roles

collection of trace evidence

provide expert testimony

document injuries/interpretation

document disease process

determine cause/manner of death

identifiy unknown descendent

forensic odontologist
forensic biologist
forensic entomologist
forensic toxicologist
forensic anthropologist
Evidence
anatomical

the body

in

ingested items

projectiles

fluids

near

weapons

on

fluids

Subtopic

trace

fingerprints

abrasions

changes

abnormal

wounds

chemical damage

punctures

trauma

normal

pathological

age related change