chapter 8 autopsy © 2012 cengage learning. all rights reserved
TRANSCRIPT
Chapter 8
Autopsy
© 2012 Cengage Learning. All Rights Reserved
2 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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.
3 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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
4 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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.
5 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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
6 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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.
7 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
Introduction
8 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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
9 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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.
10 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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)
11 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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
12 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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
13 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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
14 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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
15 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
Autopsy
Time since death (in hours) =
16 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
Autopsy
17 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
Collecting Evidence
18 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
Collecting Evidence
19 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
Collecting Evidence
20 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
Evidence
21 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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)
22 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
Toxicology
o Alcohol—gas chromatographyo Barbiturates and narcotics
• Presumptive screening—urine immunoassay• Confirmatory test—gas chromatography-mass
spectrometryo Tranquilizers—gas chromatography
23 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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
24 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
Histology
25 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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
26 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
Serology
o A forensic serologist may investigate:• Infections caused by blood-borne pathogens• Blood-typing• DNA profiles
27 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
The Autopsy Report (Obj 8.5)
o Headingo External Examinationo Evidence of Injuryo Internal Examinationo Findings and Opinion
28 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
29 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
Autopsy Report
30 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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.
31 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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.
32 Forensic Science II: Autopsy, Chapter 8
© 2012 Cengage Learning. All Rights Reserved
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.