Chapter 8 Autopsy © 2012 Cengage Learning. All Rights Reserved

Chapter 8

Autopsy

© 2012 Cengage Learning. All Rights Reserved

2 Forensic Science II: Autopsy, Chapter 8


Introduction—Objectives

1. Discuss the history of coroners and medical examiners.

2. Describe the steps of a death investigation.3. Discuss how laboratory tests are used to determine

the contributing factors that led to someone’s death.

4. Compare and contrast collection of biological and nonbiological evidence during an autopsy.

5. Describe the organization and structure of the autopsy report.



Introduction—Vocabulary

o algor mortis - postmortem (after death) cooling of the body

o autopsy - a postmortem examination of the body, including dissection to determine cause of death

o cluster - a group of woundso postmortem interval (PMI) – the interval of

time between when death occurs and the body is discovered



Madison Rutherford

o In 1998, Rutherford drove his car off the road.o The car caught fire and Rutherford died.o A $7 million life insurance policy would go to his wife,

but only after an investigation.o An autopsy revealed:

• the skull fragments were in an unlikely position• the bones indicated arthritis• the dentures records didn’t match

o Rutherford faked his death.



Introduction

o When the cause of death is unclear or suspicious:• the government requires a death investigation• performed by the medical examiner or the coroner



Introduction

o By law, deaths occurring under these circumstances must be investigated:• Violent crime, suicide, or accident• Within 24 hours of entering a hospital or having

surgery• A natural death when a doctor is not present or the

patient is not under the care of a medical facility• Occurs in police custody or in a correctional facility• Results from a communicable disease that may

pose a threat to public health.



Introduction



Historical Events (Obj 8.1)

o Two systems of death investigation exist in the US• The coroner system dates to 12C England;

sometimes the position:• is an elected official• requires a medical doctor• requires a forensic pathologist.

• The medical examiner system dates back to 1870• an experienced physician with • advanced training in pathology



A Death Investigation (Obj 8.2, 8.3, 8.4)

1. A preliminary investigation is conducted at the death scene.

2. The body is transported to the morgue, where the medical examiner examines the body and performs an autopsy.

3. The medical examiner orders lab tests on biological evidence collected during the autopsy.



At the Death Scene

o Draw sketches of the body at the sceneo Take photographs of

• the scene• the victim’s face• the underside of the body

o Document signs of traumao Estimate time of deatho Postmortem Interval (PMI)



Postmortem Interval

o The time between the death and the discovery of the body

o Evaluate livor mortis and rigor mortiso Look for scene markerso Collect evidenceo Establish a chain of custodyo Interview the victim’s familyo Check medical records and police reports



Medical Examination

o Arrival at the morgue• Update the chain of custody:

• when the body arrives, • who transported the body, and • who received the body

o Cause of deatho Mechanism of death



External Examination

o Investigate clothing and bodyo Order X-rayso Biological evidence—material from living or

once-living sourceso Nonbiological evidence—material from

nonliving sources



Autopsy

o Algor mortis—postmortem cooling of the body

o Temperature generally falls 1.5ºF every hour until the body reaches ambient temperature

o Determine body temperature• At the crime scene—rectally• At the crime lab—in the liver



Autopsy

Time since death (in hours) =



Autopsy



Collecting Evidence



Collecting Evidence



Collecting Evidence



Evidence



Laboratory Analysis

o Toxicology—the science related to the detection of drugs, alcohol, and poisons

o Histology—the study of tissueso Neuropathology—the study of disease and

trauma associated with the nervous systemo Serology—the study of blood, semen, and

other body fluids (for legal matters)



Toxicology

o Alcohol—gas chromatographyo Barbiturates and narcotics

• Presumptive screening—urine immunoassay• Confirmatory test—gas chromatography-mass

spectrometryo Tranquilizers—gas chromatography



Histology

o Slice tissue into very thin sheetso Stain the tissue samples

• Eosin (acidic)—for basic structures; • Cytoplasm appears pink• Red blood cells appear bright red

• Hematoxylin—binds to structures (e.g., ribosomes and the nucleus)

• Together—detect cancers



Histology



Neuropathology

o More than half of all deaths encountered by medical examiners are associated with the nervous system

o Common examinations:• Brain trauma• Brain cancer• Alzheimer’s



Serology

o A forensic serologist may investigate:• Infections caused by blood-borne pathogens• Blood-typing• DNA profiles



The Autopsy Report (Obj 8.5)

o Headingo External Examinationo Evidence of Injuryo Internal Examinationo Findings and Opinion





Autopsy Report



Chapter Summary

o In the US, the coroner or the medical examiner leads the death investigation when the cause of death is unclear or suspicious.

o Manner of death is classified as:• natural, • accidental, • suicide, • homicide, or • undetermined.



Chapter Summary

o The three steps of a death investigation include: • determination of the events that surrounded and

led to the death, • internal and external examination, and • laboratory analysis.



Chapter Summary

o An autopsy is performed if the cause of death is not known in order to:• document injuries, • exclude other causes of death, and • determine factors that contributed to death.

o Biological evidence is material from sources that are living or were once living.

o Nonbiological evidence is material from nonliving sources.

Documents

Chapter 8 Autopsy © 2012 Cengage Learning. All Rights Reserved