Honors Forensic Science
FORENSIC PATHOLOGY
I.
Forensic Pathology
 A. Pathology = branch of medicine
associated with the study of structural
changes caused by disease or injury
 B. Pathologist = medical doctor who
specializes in determining how disease
affects the body
 C. Forensic just adds the legal aspect to field
II. Coroner vs. Medical
Examiner
 A. Coroner
 i. Usually elected official
 Ii. Does not have to be a doctor
b.
Medical Examiner
 i. Often have both law enforcement and
quasi-judicial powers
 Ii. Operate out of centralized offices
 Iii. Usually attends crime scenes
 Iv. Duties
 1. find evidence
 2. preserve evidence
 3. report accurately
 4. also decides who gets autopsied
 A. Traumatic
 B. Unusual
 C. Sudden
 D. unexpected
II.
Autopsy
 A. Purpose – observe and make a permanent
legal record as soon as possible of the gross
and minute anatomical peculiarities of
recently deceased body
b.
Goals
 i. Determine identity of decedent
 Ii. Determine cause of death – direct agent
that leads to death (ex. Bullet, poison)
 Iii. Determine manner of death
 1. Accident
 2. Suicide
 3. Murder
 4. natural
 Iv. Determine mechanism/mode of death –
what happened to body as a result of its runin with the cause (ex. Bullet tears hole in
aorta and blood fills chest cavity)
 V. Determine time of death
 C. ME/Pathologist protocol in approaching
body for autopsy
 i. Visual inspection
 Ii. Injury inspection
 Iii. Internal exam
 Iv. Presentation to other experts
 V. Reconciliation of exhibits
 Vi. Presentation of findings (autopsy reports)
d.
Visual Inspection
 i. Prior to this blood sample taken, x-rays,
weight and measurements are done
 Ii. Begins with clothed or nude body
depending on circumstances at time of death
 Iii. Body is photographed with attention to
unusual details
 Iv. Trace evidence is collected
 V. Clothing is removed and each piece is air-
dried and packaged separately for processing
with descriptions
 Vi. Head hair combed
 Vii. Rape kit may be done
 Viii. Body openings examined
 Ix. Hands (should have been bagged at scene)
examined – ex. Damaged nails, nail
scrapings, GSR
 X. Fingerprint/footprint cards
 Xi. Entomological samples collected
 Xii. Notes of injuries and photos
 Xiii. Overall conditions of body noted
 Xiv. May use special lights to see bruises etc.
 Xv. Body mark documentation – tattoos,
scars
e. Injury Inspection –
commonly seen injuries and
causes of death
 i. Asphyxia
 1. insufficient amounts of oxygen reach the brain
or other organs
2.
Natural causes
 A. Disease that cause the respiratory system
to shut down
 i. Ex. Emphysema
 Ii. Pneumonia
 Iii. Flu
 Iv. Asthma
 V. Larynx disorders
3. Criminal means of
asphyxia
 A. Strangulation
 i. Homicide – manually or by ligature – marks on
neck are more horizontal than in suicide
 Ii. Suicide – generally see marks on neck that
curve upwards
 Iii. Accidental - rare
 Iv. Characterized by
 1. intensive heart congestion – enlarged heart
 2. venous engorgement
 3. cyanosis – blue discoloration of lips and
fingertips
b.
drowning
 i. Results from inhalation of water which
causes choking and rapid formation of mucus
in throat and windpipe
 Ii. Mucus inhibits respiration
 Iii. Characterized by
 1. foam cone covering mouth and nose
 2. fluids in lungs
iv.
5 stages of drowning
 1. surprise – person is stunned and inhales




water
2. holding breath – person tries to hold
breath while struggling
3. pink foam – person inhales deeply and pink
foam is expelled
4. respiratory arrest – thoracic movement
and pupils dilate
5. final struggle – 3-4 quick attempts to
breathe and find air
c. Smothering
 i. Occurs when airways are closed by
obstructing object
 Ii. If soft object – usually no visible sign of
trauma expect for small lacerations on lips
 Iii. Cyanosis may or may not be present
 Iv. Petechial hemorrhage – pin-point blotches
or red spots on face, typically around eyes
ii. Wounds –can often
reconstruct what happened
from types of wounds
 1. Penetrating
 A. Bullet wounds
 i. follow principles of physics
 Ii. Velocity is most important factor, not size of
bullet
 Iii. fragmenting ammunition designed to spread out
and hit vital organs
 Iv. High powered rifles more deadly than
handguns or shotguns
 V. Entry and exit wounds are important
 Vi. Entry wound generally smaller than exit
 Vii. Often able to identify caliber of weapon
from entry wound
 Viii. Often see powder burns
 1. held at distance – no other surface information
than wound
 2. held on skin – “rim burns”
 3. held a few inches away – soot on wound but no
burn – hair may be scorched
 4. held a few inches to a few feet away –
“stippling”
b.
Stab Wounds
 i. Slash wounds
 1. look like bullet wounds that graze the skin
 2. hesitation marks – often seen in suicide cases
 3. typically rectangular in shape
 Ii. Incision wounds
 1. lengths greater than depth
 2. greater amount of sub-surface tissue exposed
in almost oval fashion
 Iii. Puncture Wounds
 1. almost no geometric shape, except perhaps
circular
 2. most distinguishable from clean –cut edges
 Iv. Pre-mortem wounds gape and bleed
profusely
 V. Post – mortem wounds do not bleed
profusely
 Vi. If attacker stuck victim and twisted
object, more damage is caused and death
more likely
2.
Non-penetrating
 A. Results from clubbing, kicking, or hitting
victims
 B. Has a crushing effect on body resulting in
contusions, abrasions, lacerations, fractures,
or rupture of vital organs
 C. Red-blue contusions (bruises) almost
always present
 D. Brain contusions
 i. Difficult to analyze
 Ii. Trauma most severe on opposite side of impact
 E. Wounds to body area take longer to cause
death
 i. Due to process of subdural hematoma (blood
clot) that travels to brain
iii. Miscellaneous
 1. Rape Wounds
 A. Examination of genital area for signs of
tearing, scratching, or bruising
 B. Existence of venereal disease and/or pregnancy
 C. Foreign pubic hair, blood stains, seminal stains
collected
 D. Sometimes able to collect DNA
2.
Poisioning/Drugs
 A. Usually determinable by looking at
discolorations of body
 i. Cherry-red lividity is sign of carbon monoxide
 Ii. Other toxins give off unusual odors
 Iii,. Needlemarks between fingers and/or toes
suggest drug use
 Iv. Diagnosis requires toxicological confirmation
3.
Burn Wounds
 A. Caused by heat, a chemical or electricity
 B. Often found in “pugilistic” position with
clenched fist
 C. Heat generally causes the protein in body
to contract
 D. Electrical burns – occur in pairs; one from
point of contact, other from grounding point
where current passes out of body
4.
Traffic Fatalities
 A. Analyzed to determine if victim was driver,
passenger or pedestrian
 B. Motorcycle injuries more severe
 C. Automobile drivers often have circular
impression in chest area
 D. Passengers normally have extensive knee
and spinal injuries
 E. Pedestrian injuries
 i. Extensive lower body injuries – “bumper
fractures”
 Ii. The lower on the leg the “bumper fracture”, the
more likely it is the driver attempted to slow down
 Iii. Run-over injuries are distinguishable by
amount of compression tissue damage
f.
Internal Exam
 i. “Y” incision
 Ii. Organs removed and examined for injury
and disease and then weighed
 Iii. Stomach contents examined – may help
determine time of death and tie victim to
certain places
 Iv. Blood for toxicological screens
 V. Bladder – fluid removed for drug analysis
 Vi. Reproductive organs tested for pregnancy
 Vii. Generally, organs are replaced unless
something is amiss
 Viii. Head
 1. eyes/eyelids – sample vitreous fluids
 2. hemorrhages may indicate hanging or
strangulation
 3. cut off face to examine skull
 4. skull opened and brain examined
IV.
Special case autopsy
 A. Fetal Death
 i. A fetus of less than 500 g is “miscarried” –
expelled from mother’s body through natural or
traumatic means
 1. no autopsy is done and no death certificate is
issued
 Ii. A fetus of more than 500 g is born dead – a
still birth
 1. in absence of violence or suspicion, a special
fetal death certificate is issued with cause of death
“non-viability” of fetus
 Iii. A fetus of more than 500 g is born alive
and then dies
 1. standard death certificate
 2. autopsy usually done
b.
exhumations
 i. Order to exhume body must be obtained
from the court
 2. problems – embalmed bodies have had
blood drained and replaced with
formaldehyde compounds; remains may
have skeletonized
c. Partial
bodies/amputations
 i. Difficult to establish cause of death if entire
body is not present
V.
Autopsy Reports
 A. Pathological diagnosis
 B. Cause of death
 C. Contributing cause of death – usually a
pre-existing illness or condition
 1. ex. Pneumonia or asthma
 D. Mechanism of death
 i. Usually anything expressible only in medical
jargon
 Ii. Ex. Lung sacs became obstructed and could no
longer transport oxygen
 E. Immediate cause of death
 i. Usually gets at cause of death
 Ii. Expressed in medical jargon or in laymans
terms
 Iii. Ex. Asphyxia or wound
 F. Manner of death –
 Usually is mechanism plus immediate cause;
suicide, homicide, accidental, natural or unknown