Forensics ~ Cause & Manner of Death

Dr. Perry Lyle, PhD / March 5, 2017 / Columbia College - Orlando

How do we determine COD?There are only 5 possible modes of death, yet the causes of death may be wide and varied.

PathologyPathology is the study of disease, so forensic pathology is the study of injuries and/or disease in order to determine the cause of death.

(Merriam- Webster).

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The Medical Examiner

A medical doctor (MD) who works for the legal system to determine cause of death in legal cases. They conduct autopsies to determine not only the ultimate cause of death but also the manner and mode of death. A medical examiner is a trained professional that gains experience in forensic sciences and legal aspects of death investigations.

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Corner

The corner is usually an elected official and may not have a medical degree. They would oversee the investigation but rely on the information given to them by medical examiner to make their decisions. The corner is a middle person and most jurisdictions have eliminated the position as a cost savings to the community.

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Five Manners of Death ~ Overview

• Natural Causes

• Accidental

• Homicidal

• Suicidal

• Unknown at Time / To Be Determined Deaths from Natural Causes represented 92.5 % of all U. S. deaths, (2013)

according to the CDC (2016, February 16)

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Cause of Death

• Cause (Mode) of Death

• The medical or forensic cause:• Gunshot• Blunt force trauma• Heart Attack• Strangulation• Drowning

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Gun Shot

Suicidal

• M. E. along with police gather sufficient evidence that the gun shot wounds to the victim where self-inflicted.

Accidental

• M. E. along with police gather sufficient evidence that the wounds were due to an accidental discharge of a weapon.

Homicidal

• M. E. along with police gather sufficient evidence to support an investigation into murder.

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Time of Death

Scientists and medical experts have for centuries debated over the exact time of death and for a perfect definition to affix the time of death. We are no closer today even with our advance technologies.

• Most agree that when the vital functions of the body ceases, so does life. There are no: heart beat – (pulse), breathing, cool down of body temperature begins and brain response.

• Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, adenosine triphosphate (ATP). With out cell growth – the body dies.

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Pathology and Circumstances

Forensics Related Facts

Spackling of gunshot wounds Weapon discharged at point blank range

Trauma Tearing of victim’s flesh supports type of wound

COD Massive brain trauma – loss of blood (Exsanguination)

Near contact: muzzle of the gun is held a short distance from the skin

Appears as circular wound with blackened and seared edges

M. E. collects fired projectile Projectile consistent with weapon found at scene and owned by victim

No observable sign of trauma No signs of a struggle or violence

Cause of Death Suicide by gunshot

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Body Temperature

• Normal body temperature is 98.6˚F• Body temp of a corpse drops 1.5˚F every hour• A corpse is cool to the touch after 4-6 hours• Release gases causing body to become (bloated due to

bacteria growth) occurs and body temp can rise to 128˚F• In 24 hours the body is at the ambient temperature (Algor mortis) 

• Several days after death, Putrefaction (bacteria in the body) takes place – various gases are released by the body

(odor)• Nature and time are not kind to the dead. From moment of

death, extreme weather, bacteria, insects and predators work to destroy the remains of the body (Lyle, D., 2008, p. 57)

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Pre-autopsy Procedure

Step 1

• Conditional evidence – lividity, rigor mortis, odors, insects, position, clothing

Step 2

• Pattern evidence – bite marks, imprints, impressions, weapon marks, insertions, injuries, wounds

Step 3

• Biological evidence – grass, leaves, wood, plants, pollen, flowers, insects, worms, etc.

Step 4

• Chemical evidence – cosmetics, firearms, vehicle-related chemicals, drugs, alcohol, poisons, ink, oil, cleaning fluids, soil, glass

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Pre-autopsy Procedure

Step 5

• Physiological evidence – blood, semen, urine, fecal materials, tears, milk, bile, tissues, bone, hair

Physiologic time of death – the time that the vital functions of the body stop.

Legal time of death – as recorded on the death certificate

Approximate time of death – the time that the M.E. estimates that the person died.

Body temperature, rigor mortis, livor mortis (lividity), degree of putrefaction, stomach contents, corneal cloudiness, vitreous potassium level, insect activity, scene markers are all used by the M. E. in the estimate. (p.90).

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Autopsy “ to examine with one’s own eyes” Siegel, J. (2009 p. 87)

1. Physical characteristics of victim are documented – notes are transcribed2. Distinguishing characteristics – tattoos, scars, birthmarks, dental

impressions as needed3. Body is photographed, x-rayed, and examined with alternate light source

(black light) for stains or related of trauma, etc.4. Fingernails and toenails saved for further analysis – poisons such as arsenic

maybe detected – fluids preserved for complete toxicology report5. If there signs of a rape case, swabs are taken of oral, anal, and vaginal

cavities6. Fingerprints and palm prints taken for complete body identification7. Y-incision from shoulders down to abdomen is a standard procure to examine

body cavity8. Saw collarbone and ribs to access body organs and to complete visual

examination9. Internal organs are all removed, weighed, and measured10. Blood and tissue samples are taken from each organ11. The scalp is peeled back, skull is opened and brain is examined

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Rigor Mortis

• Begins ~4 to 5 hours after death• Stiffening of body because of lack of oxygen in muscle cells• Begins in eyelids and small muscles of jaw, then to neck and

rest of body• Is sped up by increased external temp and slowed down by

cooler temp ~ a person jogging will show signs quickly• Sets in more slowly with overweight individuals• Sets in more quickly when there has been a violent struggle

(uses up energy in muscles)• Completely sets in within 12 hours after death and lasts ~36

hours before body returns to non-rigid state ( p. 94)

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Livor Mortis

• Discoloration of skin after death (purple color)• Caused by gravity-induced stagnation and settling of red blood

cells in small blood vessels (clue that body may have been moved

• The heart stops beating, blood no longer flows• Commonly referred to as “lividity”• Occurs 6-8 hours after death• Occurs in parts of body closest to ground (gravity!) Remember, as the blood vessels deteriorates, the blood leaks

into the surrounding tissues giving it the spread appearance (p. 97)

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Body Farm

• Established in 1971 by Dr. William M. Bass, anthropologist. Now officially the University of Tennessee’s Forensic Anthropology facility.

• Started with one single body to examine decay. Today, there are now over 150 bodies (daily) in various states of purification and decomposition above and below ground, buried or in rolled up carpets, or found in open-air fields to conduct studies under all kinds of conditions, extreme and normal.

• Just about every thing we know about corpses in a state of decomposition has been studied and learned from Bass’s body farm. ( p. 108).

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Rate of Putrefaction

• The rate of putrefaction depends largely on the state of the body and physical environment in which the body lies.

• The closer to the Equator, the quicker the body enzymes and bacteria will speed up the process of decompensation.

• The body in this process releases very pungent odors and gases such as carbon dioxide, hydrogen and particularly malodorous ammonia, hydrogen sulfide and mercaptans. Mercaptan will burn if ignited.

• Diabetics actually decompose at faster rates than other due to body sugars as cited in Spitz, U., & Spitz, D., & Fisher (2006, p. 109).

Caution note: Homicide does not equal murder. Since a homicide may be justifiable, no quilt is equated from a finding of homicide, such as a police officer shooting and killing a threating suspect. The cause of death would likely be declared: Justifiable homicide – shooting.

In the same vain, pundits and government officials labor to change the terminology of suicide bombers to homicidal bombers. Their thought process is in error. A suicide bomber is simply that, a terrorist aimed at causing mass carnage and death to innocents for political and ideological gains.

Caution Notes and Myths

Myth:Some believe that the human hair and nails continue to grow after death. Not true. All cellular growth

stops. What is seen is already present. The skin shrinks due to dehydration giving the appearance that the nails, for example, have become larger.

Exculpatory evidence ~ The Brady Rule, named for Brady v. Maryland, 373 U.S. 83 (1963), requires prosecutors to disclose materially exculpatory evidence (evidence that may benefit the other side) in the government's possession to the defense (Cornell Law, N.D.).

Caution Notes and Myths

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Works Cited

CDC (2016, February 16). National Vital Statistic System. CDC. Retrieved from https://www.cdc.gov/nchs/nvss/deaths.htm

Cornell Law (N. D.). The Brady Rule. Retrieved fromhttps://www.law.cornell.edu/wex/brady_rule

Lyle, D. (2008). Forensics. A Guide for Writers. Cincinnati, OH. The Writers’ Digest.

Siege, J. (2009). Forensic Science. Great Britain. One World Publications.

Spitz, W., Spitz, D., and Fisher (2009). Medicolegal Investigation of Death (4th ed.). Springfield, IL. Charles C. Thomas Publisher.

Perry Lyle, PhD

Perry Lyle, Ph.D. brings a combined 35 plus years’ experience in the Public Safety Leadership and Private Security having held responsible positions of leadership in law enforcement, intelligence, private security and forensic investigations. He is a native of Orlando, Florida and currently resides in Central, Florida and is a criminal justice professor at Columbia College, Orlando and at PAFB. As an avid writer, he is consumed with stimulating social justice in the criminal justice system. His studies in the mid-east adds a complete dimension to multi-cultural diversity.