Forensic Autopsy Part 1 and 2

what are forensic pathologists

physicians who are trained in pathology and specialize in forensics

What is forensic pathology

branch of pathology which applies medical knowledge to the court of law

Forensic autopsy

examination of a dead body to determine cause and manner of death

what is the most important part of investigation

scene investigation

Crucial to be observant of small details:

• Does anything look out of place

• Suspicious circumstances

• staged scene, postmortem manipulation

• signs of forced entry

• drug paraphernalia

death scene investigation

scenes must be attended (pathologist or forensic investigator) in homicides, suspected homicides, and pediatric deaths.

cause of death

Why?

Manner of death

How?

Manner of death examples:

• natural

• accidental

• suicide

• homicide

• undetermined (when you know the cause but not the manner)

• pending investigation

Identification

• pacemaker

• tattoos

• finger prints

• scars

• teeth

lividity

Reddish-purple discoloration in dependent areas of the body due to gravity

Which areas are pale and which are purple

areas resting against firm surface will be pale, everything not resting will be purple

When does livity come

Evident within 30min-2hr after death (not fixed), reaches maximum 8-12hr (fixed)

Rigor mortis

stiffening of muscles due to disappearance of metabolic energy source within cells (ATP) and accumulation of lactic acid

When does Rigor Mortis appears

3-6 hr after death, fully developed by 12hr (first small muscles: face, jaw)

How long does Rigor Mortis can last

18-36hr

What is Rigor Mortis influenced by

• Activity prior to death

• temperature

• clothing

• preexisting conditions

Know how to break rigor and where to press

if you don’t you will break the bones

Rigor Mortis is rapid when

• Heavy exercise

• seizures

• fever/infection

• poisons

• electrocution

Rigor Mortis is delayed when

• Cold temperature

• thin

• Chronic disease

Warm and Flaccid

<3hr

Warm and Stiff

3-8hr

Cold and Stiff

8-36hr

Cold and Flaccid

>36hr

Clues are the most helpful in determining PMI if the person was not seen for an extended period of time:

• bank activity

• unopened mail

• missed appointments

• receipts

• text messages, phone calls, emails

• social media

Autolysis

self-digestion of cells due to enzymes

Putrefaction

Breakdown of tissue due to anaerobic bacterial activity from intestines

Postmortem changes

influenced primarily by moisture and temperature

A corpse progresses through five stages of decomposition:

• Fresh

• bloat (autolysis)

• active decay (putrefaction)

• advanced decay

• skeletonisation

manifestations of decomposition

• marbling

• skin slippage and blistering

• green discoloration

• gas formation

• scrotal swelling

• maggot infestation

• Insect/ animal activity

decomposition

can occur rapidly, <24hr in hot climates

Mummification

body dehydrated

Adipocere

gray white waxy material from breakdown of fat to acids

In what cases does Adipocere happen

Body immersed in water or in damp, warm environment

How long does it take for Adipocere to appear

Months

Post mortem interval (PMI)

how long

Place of death

how did they die

Body Farm

Observe body decomposition in different conditions fo training and medicolegal purposes

Entomology

Studying the mature flies, pupal casings and maggots can help determine PMI

Entomology

Each state of decomposition attracts a different species of insect

Skeletal Remains

Requires consultation of forensic anthropologist

What does Forensic anthropology help in

• determine if there was pre, peri, post mortem trauma

• identify if decreased had predisposing joint/ bone disease

• determine if deceased had procedures/ surgeries with implants

External Examination

• X-ray

• UV light

• Evidence collection

• Photography

• Examination of clothing

• Documentation

• Washing

• Photography

X-ray

performed on cases with gunshot wounds, sharp force injuries and pediatric deaths

Evidence collection

Cases of homicide and suspicious death the body has to be examined for trace evidence

What is being examined or collected for Evidence

• hair

• fibers

• paint

• foreign material

Collection of Rape Kit

• Fingernail scrapings

• Vaginal swab

• oral swab

• rectal swab

• pubic hair

• head hair

• underwear

Sexual assault kit

Two cotton-tip swabs used for collection of vaginal. oral and rectal specimens

Bite marks

swabbed for recovery of saliva for DNA testing

Internal Exam

Examination of all internal organs, can take several days

Different pathological conditions can be diagnosed during gross exam

• Congenital anomalies

• Trauma

• Cancer

• Infection

Internal Examination

Y-shaped incision is performed, Chest plate is removed

Examination of 3 cavities

Chest (heart, lungs), Abdomen (liver, spleen, kidneys, intestines, adrenal glands, pancreas), Cranial (brain)

Methods of Examination

All organs are weighed, examined, and sections and cultures are taken if needed

Methods of Examination

• Scalp incised

• Skull cap removed

• Dura opened

• Brain removed and examined

• Small pieces of tissue are saved in formalin

Chest Cavity

• Heart

• Lungs

• Thoracic aorta

• Rib cage

Heart

Located inside pericardial sac

Heart disease is leading cause of death

• Myocardial infraction

• Hypertension/ High Blood pressure

• Atherosclerosis

• Aortic dissection

Sudden Cardiac Death may be due to

atherosclerosis, example narrowing of coronary arteries due to cholesterol plaques

Hypertension

Lead to cardiomegaly (enlarged heart) or left ventricular hypertrophy (thick left ventricle)

Predisposes to sudden death due to:

• ruptured aortic aneurysm

• sudden arrhythmia

• Stroke

Pulmonary embolism

blood clot in the pulmonary artery(ies) which occludes flow through lungs cutting off oxygenated blood back to the heart

Who is at risk

• Recent injury or surgery

• cancer

• contraceptive medications

• immobilization for prolonged time

• genetic factors

lungs

can present as sudden death

Abdominal Cavity

• Liver

• Kidneys

• Stomach

• Intestines

• Spleen

• Pancreas

• Adrenal glands

Death Causing by issues in Abdomen

• Ischemic bowel

• Peritonitis

• GI bleeding

• Cirrhosis

• Ruptured abdominal aneurysm

• Acute pancreatitis

• Spleen laceration with bleeding

Liver

Alcohol abuse and hepatitis C are two common causes for liver failure due to cirrhosis

Spleen → Extremely rich blood supply

After trauma can lead to massive hemorrhage causing hemoperitoneum (blood in abdominal cavity)

Commonly found postmortem pathologies in Intestines

• Cancer

• Diverticulitis

• Ischemic bowel

• Ruptured appendicitis

Natural Death

• Sudden and unexpected

• Cardiovascular disease → most common leading cause in men

• Atherosclerosis

• Myocardial infarction

• Aortic dissection

• Stroke

• Ruptured cerebral aneurysm

Testing

Preliminary, Confirmatory, Gas chromatography, Mass spectroscopy

Preliminary

detects commonly used and abused drugs

Confirmatory: GC/ MS, LC/ MS

will confirm and give concentrations

Gas Chromatography

separation of multiple compounds in a mixture, appears as peaks

Mass Spectroscopy

Detects fingerprint of each compound