Pathology
Pathology
• Early forensic scientists were physicians
who were called upon to give an opinion
as to the cause of death in individuals.
• Increasingly in the US, medical examiner
programs are replacing the old system of
elected coroners, who are not required to
have training.
Pathology
• First state medical examiner system was
established in 1939 in Maryland to assist
in identification of decent, to determine the
time of death, to conduct the autopsy, and
to determine the cause of death.
• These topics comprise pathology.
Pathology
Identification of Decedent
• Regardless of who has the ultimate legal
burden, the coroner or medical examiner
works with law enforcement personnel &
others to help identify the bodies of
deceased persons.
• Few forensic endeavors offer a more
challenging & creative exercise than
establishing identification of the living or
dead.
Pathology
• Identification is essential to the completion
& certification of official documents.
• The accurate identification of decedent
permits certification of death & notification
of next of kin.
• To facilitate identification of a corpse, the
following procedures are standard:
Pathology
Physical Description
• A basic portrait parle’ of the person should
be given, much as if describing a living
person.
• Height, weight, color of eyes, hair, etc.
should be recorded. Decomposition can
affect color of skin & hair.
• Skin can blacken to appear Negroid
instead of Caucasian.
Pathology
Physical Description
• Blond hair darkens, while red or brown
hair tends to become lighter & gray.
• Weight may be overestimated due to
bloating.
• If hair color is patchy or varies near scalp,
dying is a distinct possibility & samples
should be taken for lab analysis.
Pathology
Scars & Marks
• Part of portrait parle’ are skin markings –
birthmarks, scars, etc.
• Tattoos may be especially helpful since
they may indicate some past experience
(such as military insignia), or clue as to
lifestyle (“jailhouse” tattooing), sexual
preferences, or personal interests, etc.
including the decedent’s initials or
someone else’s initials.
Pathology
Scars & Marks
• Some tattooed numbers are found such as
social security, military or prisoner of war.
• Irregular scarring may indicate the former
presence of a tattoo.
• In case of indistinct tattoos, infrared
photography, high-contrast photography, &
computer image enhancement may be
successful.
Pathology
Fingerprints
• Fingerprinting is still the mainstay of
identification techniques & the basics of
taking fingerprints from the deceased in
various states of decomposition are in
chapter 5.
• The new AFIS technology makes it
possible for fingerprint identification to be
accomplished with increasing speed.
Pathology
Photographs
• Entire body should be photographed as
well as the full face & profile. The profile is
particularly valuable in recording the
shape of the ear, feature of the face most
like a fingerprint, which may be matched to
authenticated photograph.
• Scars & distinctive features (amputations)
should be documented. Photos are shown
for possible identification of deceased.
Pathology
Age Determination
• Deceased person’s apparent age may be
roughly estimated by teeth & in case of
people under 25 the joining of bones.
• X-rays provide a basis for studying extent
of cranial & epiphyseal fusions (the uniting
of various bones serve as landmarks for
estimating decedent’s age).
Pathology
Dental Features
• Pattern of dental work, including plates,
bridges & fillings can be compared with
known dental records, plaster olds, & xrays to effect a positive identification.
• Fillings are highly distinctive & can serve
as an effective means of individualization.
Pathology
Radiological Evidence
• The presence of old bone fractures, shown
in x-rays of the body, sometimes provide a
positive identification.
• So may surgical pins, plates, pacemakers
& other implants.
Pathology
Blood Factors
• Not only do ABO blood grouping, Rh factor
& other blood characteristics provide an
additional means of identification, but DNA
testing makes the blood evidence
particularly valuable.
• DNA can also be helpful in instances of
badly decomposed or skeletonized bodies.
Pathology
Medical Indications
• A thorough postmortem examination may
reveal various diseases or conditions that
have identification value such as
hypertension, old strokes, diabetes,
Alzheimer’s disease & drug abuse.
• Presence of anticonvulsants indicates a
seizure disorder; antidepressants suggest
depression, even suicidal circumstances;
and so on.
Pathology
Other Means
• Clues to dead person’s identity may be
found at scene where body’s discovered
or personal effects secured by police or
pathologist.
• Driver’s license or other identification card
in victim’s wallet or purse may be helpful,
although mere possession isn’t conclusive.
• Monogrammed personal items (cigarette
lighter or clothing) may provide clues also.
Pathology
Time of Death
• When body is discovered, pathologist or
medical examiner make observations to
indicate approximate time of death ASAP!
• The sooner after death body is examined,
more accurate estimation of time of death.
• Time of death is estimated from changes
that occur in the body following death.
They are…
Pathology
Time of Death
• Temperature, post-mortem lividity, rigor
mortis, & putrefaction. Stomach contents &
ocular changes may also be helpful in
determining time of death.
• Temperature: rate of cooling depends on
temperature of air, way body is clothed,
amount of subcutaneous fat on body.
• Temp averages a drop approx. 1 & ½
degrees Fahrenheit per hour.
Pathology
Time of Death
• Lividity: dark purplish-blue discoloration
seen on portion of body nearest ground
caused by blood settling into body’s lower
parts due to gravity. It can determine if a
body has been moved after death or not.
• Forearms & lower legs darken due to
hanging.
• Lividity appears bout 2 hours after death
when blood tends to clot in tissues.
Pathology
Time of Death
• Rigor Mortis: Immediately after death,
body is limp due to relaxation of muscles
• After death, body begins to stiffen due to
chemical changes within muscle tissue
causing rigor mortis beginning at lower jaw
& neck & spreads downward.
• Time when rigor sets in may be as soon
as 15 minutes following death or as long
as 15 hours after death.
Pathology
Time of Death
• Average time is 5 to 6 hours after death
with upper portion of body affected after
about 12 hours and entire body withing
some 18 hours.
• Rigor mortis disappears usually within 36
hours after death beginning again with
head & neck & proceeding to lower body.
Disappearance may take from 8 to 10
hours.
Pathology
Time of Death
• Variables that affect speed of rigor’s onset
& departure include great heat & individual
differences in muscular development.
• Rough rules generally employed:
– R.M. should begin within 10 hours after death
– Whole body should be stiff within 12 to 18
hours after death
– Stiffening disappears within 36 hours after
death
Pathology
Time of Death
• Under certain conditions stiffening of
hands or arms may take place
immediately after death known as
cadaveric spasm & frequently confused
with RM.
• It occurs in cases where great tension or
excitement precedes death like drowning,
suicides, homicides.
Pathology
Time of Death
• Putrefaction: decomposition changes in
dead body caused by action of microorganisms (bacteria).
• Characterized by bloating due to gas,
darkening of face with decomposition
liquids escaping from nose & mouth,
tongue swelling, formation of fluid or gas
filled blisters, green discoloration of
abdominal skin
Pathology
Time of Death
• Temperature can affect putrefaction.
Further destruction of body is caused by
maggots & various insects.
• Flies may deposit eggs between eyelids or
lips or in nostrils within matter of minutes.
Maggots may develop within 24 hours.
• If temp above 40 degrees Fahrenheit,
various insects will feed upon the body
until it is skeletonized.
Pathology
Time of Death
• Stomach Contents: can also be used to
approximate time of death. Emptying rates
change depending on number of factors
like type & amount of food, intake of drugs
or medicine, emotional/medical condition.
• Light meal: about 2 hours; Medium meal:
about 3 to 4 hours; Heavy meal: about 4 to
6 hours or even more.
Pathology
Time of Death
• Empty stomach means death probably
occurred a minimum of 4 to 6 hours
previously. If small intestine is empty as
well, death probably occurred 12 or more
hours earlier.
• Ocular Changes: If eyes stay open, a thin
film may form on the corneal surface in a
few minutes & cloudiness may take 24
hours or longer to appear.
Pathology
Time of Death
• It is important to remember that time of
death can only be estimated and that any
estimate is subject to error based on
environmental and other variables as well
as the person determining these variables
and making the decisions.
Pathology
Autopsy
• Term postmortem examination refers to all
procedures followed by coroner, forensic
pathologist, or other qualified individual in
conduction a death investigation.
• It includes the preliminary examination,
identification of the body, photography, xraying, etc. and the autopsy.
Pathology
Autopsy
• Postmortem warranted & should be
conducted in suspected homicide/suicide
• A preliminary examination should be
conducted by physician in deaths by
criminal violence, suicides, accidental
deaths, deaths where no physician was
present, sudden deaths of a person in
good health, prison deaths & deaths that
occur in unusual/suspicious manner
Pathology
Autopsy
• When preliminary exam & investigation fail
to establish clear cause of death, autopsy
should be conducted.
• General or medical autopsy performed in a
hospital for purpose of discovering any
pathological (disease) processes in
addition to learning the cause of death.
• In contrast, medical-legal autopsy much
more complete & requires special training
Pathology
Autopsy
• It includes identifying & tagging corpse,
photo-graphing body dressed & nude; fullface & profile portraits; height & weight;
taking x-rays; examining external body,
providing detailed description of bruises,
ligature marks, gunshot or stab wounds,
etc.; dissection & examining internal body;
lab testing organs & body fluids for drugs
& poisons; & rendering opinion, adding
“cause of death” to death certificate.
Pathology
Autopsy
• In actual dissection of body, thoracoabdominal (chest-belly) cavity opened
most often with Y-shaped incision
beginning at each armpit area & running
beneath breasts to lower end of breastbone continuing downward through middle
of abdomen to pubis.
Pathology
Autopsy
• Next, front portion of ribs & breastbone
removed as a unit, exposing most of
organs for examination.
• Next, heart & lungs together with trachea
& esophagus are taken out.
• Abdomen is given general exam prior to
removal of organs. Fluids are aspirated
(drawn out) so they can be analyzed.
Pathology
Autopsy
• Each organ is weighed, examined
externally, sectioned for internal study.
• Any fluid in thoracic pleural cavity (chest
lungs) is aspirated for later analysis.
• Tissues from organs are mounted on slide
for study of cellular changes.
• Contents of stomach are measured,
recorded, & sampled for toxicological
analysis.
Pathology
Autopsy
• In pelvic area, genitalia are examined with
regard to any injury or foreign matter.
Vaginal & anal swabs are taken during
external exam.
• Blood, semen, hair samples collected for
lab analysis. Urine collected from removal
of bladder so certain drugs that tend to
concentrate there (Valium & barbiturates)
my be detected by toxicologist.
Pathology
Autopsy
• Finally, head is examined beginning with
eyes. To remove brain, incision is made
across top of head, scalp is pulled forward
& skull exposed.
• A saw is used to cut through top of skull so
brain may be examined, removed (after
various nerves, blood vessels & other
attachments are cut), weight & section for
later microscopic review.
Pathology
Autopsy
• When finished, large incisions are sewn
shut. Microscopic specimens are studied,
chemical analyses are conducted in lab.
• This completes autopsy after which
medical examiner synthesizes findings &
attempts to determine “cause of death”
along with contributing factors.
Pathology
Autopsy
• Results are presented as formal “autopsy
protocol”, a legal report & file, typically a folder
that includes photographs, x-rays, fingerprints, &
toxicological test results.
• Report includes: external exam (description of
clothing, description & identification of body),
evidence of injury (external & internal), central
nervous system (head & brain), internal exam of
chest, abdomen & pelvis, toxicology test
findings, opinion.
Pathology
Cause of Death
• For investigative purposes, it is important
to distinguish between the cause, manner
& mode of death.
• Cause of death: pathological condition
producing death (subdural hemorrhage)
• Manner of death: physical agent or
instrument that was employed (blunt-force
injury to skull)
Pathology
Cause of Death
• Mode of death: indicates intent or lack
thereof when instrument was used & by
whom (homicide by person(s) unknown).
• Possible scenario: Cause – myocardical
infarction (heart attack), manner –
arteriosclerosis (hardening of arteries), &
mode – natural.
• 4 modes of death: natural, accidental,
homicidal & suicidal.
Pathology
Cause of Death
• Findings in autopsy are critical in
determining cause of death. Example:
Absence of firearm at scene would
suggest homicide, while presence of
suicide note would, if proved genuine, be
an indication of suicide.
• “Psychological autopsy”: investigation of
decedent’s mental state prior to death
conducted as aid to determine if suicide
Pathology
Cause of Death
• Asphyxia: death caused by lack of oxygen.
In suffocation, passage of air is block such
as pillow over face with possible bruises &
abrasions inside victim’s upper lip.
• Suffocation may be accidental such as by
food obstruction of which foreign material
should be revealed during the autopsy.
Pathology
Cause of Death
• Deaths by strangulation (when homicidal)
may be indicated by presence of fingertip
bruises on neck. Fingernail marks may be
present in manual strangulation. Ligature
strangulation will be indicated by presence
of groove or other marking on victim’s
throat. At autopsy, strangulation may be
indicated by fractures of larynx including
hyoid bone.
Pathology
Cause of Death
• In case of asphyxia by hanging, signs of
violence, particularly about the neck, may
be an indication of prior strangulation. If
body is found not to be completely
suspended, death is probably suicide,
since murderer would strive to completely
suspend body. Hanging is common means
of suicide but is relatively rare as form of
homicide or accidental death (except in
the case of children).
Pathology
Cause of Death
• Drowning deaths are also due to asphyxia.
Air in lungs replaced by fluid, so victim
chokes. Irritation of mucous membranes
results in formation of great deal of mucus
in throat & windpipe. Efforts to breathe
produce a sticky foam which may be
mixed with vomit. Foam prevents passage
of air into lungs.
Pathology
Cause of Death
• Drowning indicated by presence of white
foam. Other indicators may be articles
found grasped in hand & swelling of lungs.
• Asphyxia may be caused by blow to neck,
(karate chop) or compression of chest
(pinned under collapsed building). Cherryred lividity may indicate asphyxia by
carbon monoxide poisoning & can be
determined by autopsy.
Pathology
Cause of Death
• Blunt-force Injuries: usually directed at
head. Internal organs may suffer without
external indication of violence. Blows to
head reveal fracture of skull; chest may
produce broken ribs that pierce lungs or
heart or cause heart to be crushed or
ruptures; blows to abdomen may produce
ruptured spleen, liver, or kidney & may
result in death from hemorrhage.
Pathology
Cause of Death
• Burning Deaths: by fire typically cause
corpse to assume a distorted position
somewhat resembling a boxer’s pose. It
occurs if person is alive or dead since
effect is simply contracted muscles. If
alive, smoke stains around nostrils &
carbon monoxide in blood. In case of skin
burned without attendance singeing body
hair or clothing, scalding by hot liquid or
steam is indicated.
Pathology
Cause of Death
• Electric shock: death by electrocution not
ordinarily produce a characteristic
appearance. Pulmonary edema (swelling
of heart) & appearance of asphyxia may
be present.
• High voltage electrocution is likely to
produce visible burns on body, while 1/3 to
½ of low voltage electrocutions leave no
burns.
Pathology
Cause of Death
• Gunshot wounds: Bullet wounds two basic
types: entrance wound & exit wound.
• Entrance wound smaller than exit wound
as well as rounder & neater with black ring
of discharge products around edges &
comparative lack of bleeding.
• Exit wound more ragged in appearance &
has shredded tissue extruding from wound
& more profuse bleeding.
Pathology
Cause of Death
• Wound Location important. In murder, may
be found anywhere; in suicide tendency to
be in right temple, mouth, beneath chin,
center of forehead, center of back of head,
or left chest. Majority in right temple, gun
held tightly against skin to produce starshaped “contact” wound. Presence of
weapon tightly gripped in hand a strong
indication of suicide.
Pathology
Cause of Death
• Appearance of gunshot wound affected by
many factors; firing distance, type of
weapon & ammunition, passage through
clothing, part of body affected, & factors
like ricocheting. Distance between firearm
& wound given by presence of “tattooing”
or “stippling” (pinpoint hemorrhages from
discharge of burned gunpowder) indicating
a relatively “close shot”.
Pathology
Cause of Death
• Motor Vehicle Fatalities: traffic accidents
present special circumstances. Hit & run,
clothing should be carefully scrutinized for
grease, tire marks, glass fragments or
paint. Leg bones are frequently fractured
by bumper contact & height in relation to
soles of feet should be measured for
comparison with forwardmost part of
bumper.
Pathology
Cause of Death
• Trauma associate with driving of vehicles
having suffered impact may be severe.
• Impacts from front often transversely
fracture sternum (breastbone) & cause rib
fractures on sides of chest.
• In young adults, ribs & sternum may be
unbroken due to relative elasticity, while
there are crushing injuries to the lungs &
heart.
Pathology
Cause of Death
• Poisoning: murder by poisoning is
extremely rare. Usually are suicidal or
accidental & involve narcotic overdoses or
inadvertent taking of wrong medications.
• Only a few are commonly used for murder.
Arsenic & antimony most common &
metallic poisons. Insecticides, rat poisons
& even certain medicinal preparations are
used as poisons.
Pathology
Cause of Death
• Symptoms of poisoning by arsenic include
vomiting, cramps, & diarrhea, possibly
bloody diarrhea. Death may occur in a
few hours or in several days depending on
the dosage used – small amounts,
increasing doses, or a large dose all at
once.
Pathology
Cause of Death
• Arsenic may be detected in body many
years after death. Detection doesn’t
indicate murder
• Less commonly used antimony: industrial
& medicinal (including veterinary) uses.
Symptoms include intensive gastric
irritation & pain, metallic taste in mouth,
vomiting of bloody material, diarrhea,
sweating, rapid pulse & muscle spasms.
Pathology
Cause of Death
• In fatal cases, there may be delirium,
subnormal temperature & collapse.
• Poisoning may be acute (sudden) or
chronic (incremental).
• Stabbing: stabbing & cutting wounds may
cause death themselves or lead to
complications like tetanus or pneumonia
that represent a secondary cause of
death.
Pathology
Cause of Death
• Rarely are cutting or stabbing deaths
accidental; usually they are the result of
suicide or homicide. In suicide, the left
wrist, left chest, throat & femoral artery are
most commonly attacked locations.
• Sometimes wounds accompanied by
superficial cuts called “hesitation marks”
(indicating tests before person summons
enough nerve to inflict fatal slash).
Pathology
Cause of Death
• Their presence is strong indication of
suicide, as is weapon being clenched in
deceased person’s hands, indicating
cadaveric spasm. In suicides body
remains at site of fatal cutting or stabbing.
• In homicide, body may be moved and a
blood trail of victim attempting to flee
assailant may be present.
Pathology
Cause of Death
• Whereas suicide may be accomplished by
cutting only, murder has stabbing strokes
as a means of efficient killing. Fatal
wounds from homicide usually occur in
neck or upper chest. Wounds in back are
indicative of murder. Sometimes victim
receives cuts on palms or outer forearms
that result from attempts to wad off attack
known as “defensive wounds”.
Pathology
Cause of Death
• An examination of wounds by medical
examiner may permit an estimate as to
type of weapon, its size, shape &
sharpness.
• The wound dimensions & depth of
penetration are useful indications of the
weapon’s characteristics.
Pathology
Death of Marilyn Monroe
• Watch Video & Do Video Quiz on the
Death of Marilyn Monroe.
• After watching video and reading case
study in book answer the following
question: Do you think Marilyn Monroe’s
death was an accidental suicide or a
homicide? Were the Kennedy’s & or FBI
involved in your opinion?