Death investigation process
Death investigation
Evidence
anatomical
the body
changes
normal
age related change
pathological
abnormal
trauma
wounds
punctures
chemical damage
abrasions
on
fingerprints
trace
Subtopic
fluids
near
weapons
in
fluids
projectiles
ingested items
Experts
forensic anthropologist
forensic toxicologist
forensic entomologist
forensic biologist
forensic odontologist
forensic pathologist
Roles
identifiy unknown descendent
determine cause/manner of death
document disease process
document injuries/interpretation
provide expert testimony
collection of trace evidence
coroner
roles
physician or “lay” person
order investigations or inquests
determine need for further tests/investigators
access decedent medical records
determining cause/circumstances for
unexplained deaths
unexpected deaths
unnatural deaths
police homicide investigator
medical examiner
roles
chief/deputy chief
forensic pathologist
Medical doctor
Purpose
provide answers to family members
prevent similar deaths
population statistics on morbidity/mortality
assist in administration of justice
objectives
identification
cause of death
manner of death
post- mortem interval
public health and policy
reportable deaths
violence
medical misadventure
negligence
misconduct
malpractice
during/following pregnancy
suddenly/unexpectedly
disease/sickness not treated by qualified medical expert
non natural
overdose
accident
death in care
long term care facility
psychiatric hospital
prison
during work
Autopsy
clinical
hospital
treating with consent
extent of disease to treat descendant
medicolegal
forensic
does in legal authority
sudden/suspicious
obscure/unnatural
cause of death
physiological derangement in the body
strangling
mechanism
final physiological derangement
asphyxia
manner
circumstances surrounding death
natural,
homicide
undetermined
accidental
suicide
Entomology
stages of decomposition
advanced decay
odor is less obtrusive than in the previous stage
large amount of the flesh removed
dry stage
arcass has been reduced to bones
insects are still present at this stage.
active decay
very strong putrid odor
due to the gases escaping from the body
bloated
bloated appearance
obvious odor present at this time
few morphological changes are observed
Chemical breakdown occurs
post mortem interval
entire period after death
Insects are cold blooded
develop faster at warmer temperatures
larvae tissue
extracting human DNA
Applications of forensic entomology
- Post mortem interval
- Neglect
- Endotoxicology
- Extracting human DNA
- Disposal of body
- Movement of the body after death
disposal of body
location will affect decomposition and insect colonization
Larvae may move clothing to appear like a sexual assault took place
Feed on tissue around a wound, destroying evidence
blowflies
life cycle
adult
larvae
pupae
egg
beetles
beetles eat larvae
Board Certified Forensic Entomologist
promote education
research
practice of medico-legal entomology
study of insects and other arthropods
forensic biology
Human genome project
Mapped entire human genome
Genes are approx 5% of human DNA
justice system
law enforcement
police agencies
laws police training
scientific analyses
forensic laboratory
CSI
Serology evidence exam
evidence submitted from investigators/police
testing performed to look biological fluids
non specific but indicated potential presence of biological
case work
case consultation with police
make a comparison between the reference samples
report writing
examinational testing and interpretations
research
develop new techniques and validate new tech
Teaching
Special case work
Audits
Cold cases
STR DNA profile
each marker will have two alleles
combination of alleles at reach
DNA testing
profile by itself is fairly useless
Crime scene compared to suspects
forensic art
any art that is an forensic nature
Purpose
recreate an artistic rendering of the face
of an unidentified individual
Professional relationships
- forensic pathologists
- forensic anthropologist
- forensic odontologist
Human recognition
- recall recognition context
- recognition is holistic
Likeness
goal for everything
combined with facts and details can combine to create solid investigation leads
Composite drawing
- witness sees suspect face
- witness believe they recognize them of they saw them again
- cognitive interview
- unlocking memory codes
Composites
objects/markings
Age progression
Manner of death
Canadian death investigation
coroner
medical examiner
public health
police services
coroner
pathologist
consultant
other agencies
forensic scientist
stages
notification
preparation
scene analysis
post scene analysis
verification
reporting
coroner jurisdiction
purpose
in public interest
answer five questions
what they need
what
where
demographics
evidence body
by what means
how
medical history
circumstances
medications
Who
demographics
documents
prints
DNA
scenes to treat carefully
warrant for post mortem
speaking to families
Investigation power
warranty authority
body possession
post mortem
burial
non warranty authority
enter/inspect
seize anything
extract info
delegate power
roles
law enforcement
any finding legal
compel law
collect/analyze forensic evidence
deaths investigated
specified natural
Post scene analysis
responsible
Homicides
police
joint investigation
fire death
fire marshal
emergency management
rail deaths
rail investigators
transportation safety board
undetermined
yielded
insufficient evidence for any
specific classification
Injury interperation
Types of injuries
Blunt force
occur when
struck with
strikes with
blunt object / surface
produces
scraping
shearing
tearing
crushing
Laceration
tear in tissue
caused by
crushing force
shearing
Fracture
break in the bone
Bruise
Contusion
Scrape/brush abrasion
impact abrasion
patterned abrasion
Variation of an impact abrasion
Imprint of the object
imprinted/stamped onto the skin
Abrasion
removal of superficial layer of skin
produced from
friction against a rough surface
destruction of superficial layers by compression
Force varies with mass of object
nversely varies with the duration
calculation
Force = mass x acceleration = kilogram x (meter / second2)
defense wounds
during active defense from weapon
caused by pointed/sharp edged
Stab wound
depth of wound
sharp edges around wound
Incised wound
deep wound
straight edges
Chop wound
heavy sharp object creating the wound
alive and alert at the time of injury
injury is blunt or sharp
Asphyxia
Failure of cells to receive or use oxygen
Death due to cerebral asphyxia
classifying
Mechanical asphyxia
External next compression
Chemical asphyxia
Plastic bag asphyxia
Drowning
Mechanical asphyxia
Pressure on the outside of the body
Traumatic asphyxia
large heavy object compressing chest
Positional asphyxia
body position compromises breathing
Crush asphyxia
pressure
Manual strangulation
Ligature strangulation
Hanging
Choke holds
Autoerotic asphyxia
Chemical asphyxia
Displacement of oxygen
Carbon monoxide
Hydrogen sulfide
Cyanide
electricity
Electrocution
Lightning strike
environment
Cold environment
Frostbite
Hypothermia
Hot environment
Heat stroke
heat exhaustion
Environmental hyperthermia
fire
Burns and thermal injuries
Smoke inhalation
External Examination
Body with pugilistic attitude
Due to heat effect
skin
burn marks
Longitudinal splits
Protrusion of abdominal contents
extremities
Soft tissues burn away and bones can fracture
white translucency of corneas
epidural or extradural heat
firearm
Wound pattern depends on
type of firearm used
type of ammunition used
range of fire
distance between the firearm muzzle and tissue
Pathologic range of fire
Contact
Close
Intermediate
Distant / Indeterminate
entrance gunshot wound
skin
circular or “punched out”
bones
internal beveling
exit gunshot wound
skin
irregular
stellate
slit-like appearance
bones
external beveling
types
revolver
derringer
single- shot pistol
handgun
machine gun
shotgun
genetics
inheritance
living things have set of characteristics/traits
inherited from parents
mendelian genetics
invisible factors ; predictably determining trait of an organism
Non mendelian genetics
Mendelian traits are controlled by a single locus
one-gene equals one-phenotype
Sickle cell anemia
cystic fibrosis
some muscular dystrophies
don’t explain some patterns of genetic inheritance
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
Co-dominance
phenotypes produced by both alleles clearly expressed
Incomplete dominance
one allele not completely dominant over other allele
Polygenic traits
interaction of several genes
Mendel's law
states that alleles segregate equally and independently
Second law
law of independent assortment
Third law
States that recessive alleles will always be masked by dominant alleles
Galton says traits
Phenotypes grade imperceptibly from one category to the next
DNA = deoxyribonucleic acid
Two stranded that coil around each other to form a double helix
enzyme that synthesizes new DNA from existing DNA template
Transcription
process by which RNA polymerase turns genes into RNA
orcherstrated by the ribosome
Forensic anthropology
Death investigation teams
- police homicide investigator
- forensic pathologist
- forensic odontologist
- ballasts
Forensic significance
material to criminal investigation/trial in court of law
- Re-evaluated throughout analysis
- basis of full search
- always significant until proven otherwise
Taphonomy
effects of environment on bone from death to recovery
Expert report and testimony
- reports submitted
- relevant case info
- all parties attending
- statement of forensic significance
- biological profile
- analytical findings
- expert interoperation of data
casework
- images from police
- fire recovery
- found human remains
expertise
field to lab to court
- reconnaissance
- search design
- search
- recovery
- documentation
- analysis
- expert witness testimony
Reconnaissance
- Do not enter the scene
- aerial photograph
- maps contemporary
- perimeter photography, video, sketches ]
- intangible evidence
Search design
- direct or remote
- terrain
- time of year
- hazards
- search purpose
- budget
- available personnel
Search methods
- line searching
- walking
- hands and knees
- uphill/downhill
- equipment
Documentation
- occurs at each step
- mapping
Recovery and transportation
- method matches specimen
- bones
Chain of custody
Document any item removed from scene
Analysis
mini- minimum number of individuals
Biological profile
- age
- sex biogeographical affiliation
- stature
- trauma/pathological conditions
Purpose
- aid the forensic pathologist
- identification
Forensic pathology
Subtopic
provide answers to living family members
data for population statistics on morbidity/mortality
plan for health policies
information to agencies that provide benefits
prevent similar deaths
through recommendations
through genetic testing
determines cause of death by performing autopsy
investigation of cause and manner of death by the performance of medicolegal autopsies
Roles
Determine cause, mechanism, and manner of death
identification of an unknown decedent
postmortem time interval and time of injury
Degree of decomposition
collection of trace evidence
Document injuries / Interpret
Document disease processes
Provide expert testimony
Objectives of death investigation
1. Identification of decedent: “who”
2. Time (date) of death: “when”
3. Location of death: “where”
4. Cause of death: “how”
5. Manner of death: “by what means”
6. Recognize practices / conditions that could have led to death
medical examiner
Qualified pathologist; training in death
investigation/forensic pathology
Performs death investigation
Certifies cause and manner of death
Medicolegal Systems
In Canada and USA, Coroner may be physician
Coroner certifies manner of death
Scientific identification
Fingerprint comparison
based on finger ridge patterns
Odontology
Comparison of dental fillings
distinctive configuration of bony structures of jaw
teeth roots and nearby sinuses
Deoxyribonucleic acid
Nuclear DNA
mitochondrial DNA comparison
Radiology
Comparison of distinctive markings or characteristics
Medical hardware
Medical device with unique serial number
Medicolegal autopsy
steps
History, Scene & Circumstances
Medical and social history
Environment
body position
clothing
medications
External examination
Collect physical evidence
Collect biologic samples
Trauma
Internal examination
Dissect organs and tissues
Look for disease/injury
Ancillary studies
Clinicopathologic diagnosis
Summarize findings in report
Provide opinion on cause of death
factors of death
toxicology
poisoning
Intoxication with drugs
microbiology
Infection
immunocompromised
non-vaccinated
Non scientific identification
Visual identification
Physical attributes/profiling
age
sex
stature
healed injuries
congenital conditions
Distinctive marks
Circumstantial evidenc
belonginigs
documents
clothing
Forensic entomology
Succession pattern of insects
collection of trace evidence
evidence that may indicate sexual activity
evidence that link decedent with another individual
Injuries
- Blunt force
- Sharp force
- Firearm
- Asphyxia
- Environment
Diseases
interpret contributed to or caused death
Examine all organ systems of the body
disease has a heritable component
expert of testimony
event has legal or civil proceedings
Summoned to court under a subpoena