Introduction to Autopsy Pathology

What is the major difference between a Medical Examiner (ME) and a Coroner?

Appointed physician (usually a forensic pathologist)

Often an elected lay official who may not be medically trained

What is postmortem redistribution (PMR)?

Drug/toxin concentration changes after death as tissues release stored compounds into blood

Which system is more common in large US cities/many states: ME or Coroner?

ME system

What are the main duties of a forensic pathologist?

Determine cause and manner of death

Perform/Supervises autopsies

Collect evidence

Certify death certificates

Testify in court

Contribute to public health surveillance

Why were coroners originally established in England?

To protect the Crown’s financial interest and investigate suspicious or sudden death

Who has legal authority over the body and death scene in medicolegal cases?

The ME/Coroner

Which deaths generally fall under ME/Coroner jurisdiction?

Sudden, unexpected, or unexplained

Violent (homicide, suicide, accident)

Suspicious/Unusual circumstances

Unattended (~24 hours)

Custody-related (prison, jail, police encounter)

Unknown, death certificate cannot be completed

Stillbirth → DOA cases

Why are deaths in custody automatically medicolegal cases?

Due to legal/public accountability

Potential concern for violence, neglect, or misconduct

What does DOA stand for and why is it important in forensic pathology?

Dead on Arrival

Often requires medicolegal investigation if cause is unknown

Can law enforcement overrule the ME/Coroner regarding jurisdiction over the body?

They cannot override

Define CAUSE of death

The disease or injury initiating the sequence of events leading to death

Define MECHANISM of death

The physiologic derangement producing death; The “How”

• Ex. Arrythmia, exsanguination

Why should “cardiac arrest” NOT be listed alone on a death certificate?

It is a mechanism, NOT an etiologic cause of death

What are the five MANNERs of death?

Natural

Accident

Homicide

Suicide

Undetermined (used judiciously)

Define MANNER of death

The circumstances under which the cause of death arose

What is the difference between homicide and murder?

Medical classification (pathologic)

Legal determination

What is considered the immediate cause of death?

The final disease or injury directly leading to death

Listed on line (A) of the death certificate

What is the underlying cause of death?

The disease or injury initiating the fatal sequence

Listed on line (B) or (C) of the death certificate

Why is “undetermined” manner of death used cautiously?

Is should only be used when evidence is genuinely insufficient

Why is context important for drug toxicity?

It could be labeled accident, suicide, or undetermined

What determines if falls in elderly is accident vs. undetermined?

When pre-fall illness is present

A gunshot wound to the chest causing exsanguination would have what causes and mechanism?

Cause → Gunshot wound

Mechanism → Exsanguination

What is a medicolegal/forensic autopsy?

An autopsy ordered by the ME/Coroner to determine cause and manner of death

Does an autopsy require family consent?

Medicolegal → No

Clinical/Research → Yes

What is the purpose of a clinical (hospital) autopsy?

To clarify diagnosis, disease process, or treatment outcome

Which type of autopsy always requires explicit consent?

Scientific/Research autopsy

What is a virtual autopsy?

Use of CT/MRI imaging as an adjunct to standard autopsy examination

Why has the decline in hospital autopsies been problematic?

Reduced quality assurance data and fewer opportunities to identify diagnostic errors

Who may consent for a hospital autopsy?

Next of kin according to statutory hierarchy

• Spouse → Adult children → Parents → Siblings → Other

Can religious objections prevent a medicolegal autopsy?

Usually not if public interest requires the examination

What is the overall purpose of an autopsy?

Establish cause/manner of death for legal certification

Positively ID decedent

Collect/Document evidence

Provide information to surviving family

Education

What is a discrepancy between clinical and autopsy diagnosis?

Autopsies support quality assurance in clinical medicine

Who in also involved for federal cases in autopsies?

May involve separate statutory authorities (DoD, FBI)

What is unique about partial or limited autopsy consent?

Hospital → Permissible

Forensic → Must document any restrictions

Why is scene investigation critical in forensic pathology?

Autopsy findings cannot be fully interpreted without scene context

What phrase summarizes the importance of scene documentation?

"The scene is ephemeral; The autopsy is permanent”

What environmental factors profoundly affect postmortem change rates?

Temperature

Humidity

Insect activity

Body position

Lividity patterns

What should be documented when on scene prior to moving the body?

Photographs

Diagrams

Written notes

What must reconcile with autopsy findings?

Body position

Lividity patterns

Scene context

What should be documented before removing clothing?

Blood stains

Tears

Defects

Trace evidence

Preserve for crime lab

What type of findings are important during skin examination?

Scars

Tattoo

Abrasions

Contusions

Puncture marks

Petechiae

Lacerations

Document location with body diagrams

What injuries may suggest strangulation/asphyxia?

Petechiae and ligature furrows

Where are defensive injuries commonly found?

Dorsum of hands and forearms

Why are posterior body surfaces always examined?

Important injuries or lividity may otherwise be missed

What is often collected on scene for toxicologic and clinical interpretation?

Medication

Drug paraphernalia

Medical equipment

Who is interviewed prior to performing an autopsy?

EMS
Law enforcement

Witness

Treating physicians

What forms of identification are recorded in external examinations?

Clothing label

Personal effects

Hospital ID band

Fingerprints

Dental charting

Radiographs

What body habitus’ are recorded in external examinations?

Height

Weight

Estimated age

Body condition

What parts of the body are focused on in external examination?

Head and face → Eyes, ear, nose, mouth

Neck → Natural vs. Ligature

Extremities → Defensive injuries, injection sites, restraint marks, fractures

Genitalia → Sexual assault; Collect swabs before internal exams

Posterior surfaces

What incision is commonly used in autopsies?

Y-incision from shoulders to pubic symphysis

What is hemopericardium?

Blood accumulation in the pericardial sac

Why are coronary arteries serially sectioned every 3-5 mm?

To evaluate for stenosis or thrombosis

Why is the brain fixed in formalin for at least 2 weeks?

To improve neuropathologic examination/sectioning

What is the difference between Rokitansky and Virchow?

Organs removed en bloc

Organs removed individually

What is the standard protocol for an internal examination?

Y-incision

Reflect chest plate

In situ inspection

Evisceration

Organ weight and documentation

What are removed as indicated by circumstances?

Spinal cord

Eyes

Middle ear

What is the gold standard blood source for toxicology?

Femoral blood

Why is vitreous humor valuable in toxicology?

Less affected by postmortem redistribution

What are commonly collected for toxicology?

Femoral blood

Vitreous humor

Urine

Bile

Liver

Gastric contents

What evidence should be collected in suspected sexual assult cases?

Oral, vaginal, rectal swabs

Fingernail scraping

Clothing

Photographs

How should projectiles be removed?

Recover with rubber-tupped forceps or by hand

Why should projectiles not be removed with metal forceps?

Metal can scratch ballistic markings

What is chain of custody?

Continuous documented control of evidence from collection to court

Why are fingernails collected in suspected struggles?

They may contain assailant DNA or trace evidence

What is considered trace evidence and how should be collected?

Gunshot residue

Hair

Fibers

Glass

Collect with tape lifts before washing the body

What is the purpose of histology and microbiology during autopsy?

Formalin-fixed tissue from all major organs; Additional fresh tissue for metabolic/genetic studies

Fresh tissue, blood cultures if sepsis or infectious disease suspected

What is algor mortis?

Postmortem cooling of the body

What is the general rate of body cooling after death?

Approximately 1-1.5 C/hour under standard conditions

What is the difference in wound vitality between perimortem and postmortem?

Green-stick fractures, longitudinal splits, parallel fractures, radiating lines — bones retain elasticity

Irregular, dry fractures; Jagged edges; No hemorrhage or soft tissue injury

What does PMN infiltration indicate?

Antemortem injury (inflammation)

No inflammation = questionable

What factors accelerate algor mortis?

Cold environment

Lean body

Wet skin

Air movement

What factor slow algor mortis?

Obesity

Insulating clothing

Warm environment (paradoxically slower)

What is the plateau phase of algor mortis?

Early after death

Body may maintain temperature 1-2 hours (“lag phase”) before rapid decline

How is algor mortis untilized in forensics?

Most useful within 24 hours

Reliability decreases sharply after ambient equilibration

How do you accurately measure algor mortis temperature?

Rectal (preferred for scene)

Tympanic

Liver temperature using a calibrated thermometer

What cases livor mortis?

Gravitational settling of blood after circulation stops

When does livor mortis begin (onset)?

About 1-2 hours after death

When does lividity become fixed (fixation)?

Approximately 8-12 hours after death

What are four key pieces of knowledge essential about postmortem changes?

Estimating PMI

Distinguishing antemortem from postmortem injuries

Interpreting toxicology results accurately

Avoiding misinterpretation of decomposition artifacts as injuries

What are primary postmortem changes?

Livor mortis

Algor mortis

Rigor mortis

What are secondary postmortem changes?

Decomposition (autolysis)

Putrefaction

Adipocere

Mummification

Skeletonization

Can one postmortem change be used as evidence?

No single marker is precise alone

What does cherry-red lividity suggest?

Carbon monoxide poisoning

Cyanide poisoning

Hypothermia

Bright red due to carboxyhemoglobin or oxyHb preservation

What does lividity inconsistent with body position suggest?

The body was moved after death

What is contact flattening?

Pale areas where pressure prevented blood settling

What is absent lividity?

The body fails to develop the characteristic purplish-red skin discoloration after death

• Causes → Profound anemia, hypovolemic shock

Widespread lividity in polycythemia

What is another name for area of contact pellor?

Area of blanching

What causes rigor mortis?

ATP depletion causing persistent actin-myosin cross-bridging

When does rigor mortis begin?

About 1-6 hours after death

When is rigor mortis maximal?

Around 12-24 hours postmortem

When does rigor mortis resolve?

Typically within 48-72 hours

What is cadaveric spasm?

Instantaneous rigor preserving the position at death

What happens if rigor mortis is forcibly broken?

It does NOT recur in that muscle group

How reliable is rigor mortis?

Useful within first 24-36 hours

Environmental variability limits precision

What does this represent?

Approximate landmark for postmortem intervals

These are estimates

Combine algor + livor + rigor for best PMI estimate

What is more accurate than physical signs after 72 hours?

Entomology (insect succession)

What is autolysis?

Self-digestion by endogenous enzymes after death

What is pseudomelanosis?

Green-black discoloration of skin and intestines from sulfhemoglobin formation

Which organ autolyze most rapidly?

Pancreas

Brain

Adrenal glands

When and where does bloating occur?

2-3 days in warm weather

Face/Scrotum/Abdomen prominent