Under the Microscope

Welcome to “Under the Microscope,” Killer Nashville’s very own exclusive Forensics Corner. We hope to unearth, demystify, and in general, bring you interesting, factual information about the world of forensics from experts in various fields. From dead bodies, to suspicious substances, to computers seemingly with a mind of their own, this column will explore the at-first possibly macabre, gory, and unexplainable and then explicate the truth in scientific terms for writer’s to use at their will.

For the next three issues, physician, author, former Killer Nashville Guest of Honor, and one of the nicest guys on the planet Dr. D.P. Lyle, will share critical information about the business of death and the elements of a great investigation.

Cause and Manner of Death

By D.P. Lyle


Cause and Manner of DeathIn this three part series I will discuss two of the most critical determinations that the coroner or medical examiner must make in any potential homicide: The Cause and Manner of Death and The Time of Death. Whether an investigation is begun or not depends on the former. If the manner of death is natural, no criminal investigation will follow. The same is true of most cases of suicide or accidental death. But if the medical examiner determines that the manner of death is homicidal, then the investigative folks go to work.

Time of death is critical in that it is the linchpin of the crime timeline and can support or refute witness and suspect statements and explode alibis. It is the ticking clock around which all else revolves.


In any potentially criminal death, the coroner or Medical Examiner (ME) is asked to answer three basic questions: How did the person die? Why did the person die? When did this person die? In forensic terms, these are the cause, manner, and time of death, respectively. 

People die every minute of every day, but only a very few of these attract the attention of the medico-legal investigative system. To the forensic professional it is the cause and manner of these deaths that are of paramount importance.

The cause of death is why the individual died. A heart attack, pneumonia, a gunshot wound, drowning, or traumatic brain injury from an automobile accident or a fall from a high building are causes of death. They are the diseases or injuries that caused death. This is fairly straightforward and, in most cases, easy for the coroner to determine.

The manner of death is a bit trickier. It can be defined as the root cause of the sequence of events that lead to death. In other words, how and why did these events take place? Who initiated the events and with what intention? Was the death caused by the victim, another person, an unfortunate occurrence, or Mother Nature?


The five manners of death:


Natural: Death from natural disease processes. Heart attacks, cancers, pneumonias, and strokes are common natural causes of death. This is by far the largest category of death that the coroner sees.



Accidental: Death from an unplanned and unforeseeable sequence of events. Falls, automobile accidents, and electrocutions are examples.



Suicidal: Death by the person’s own hand. Intentional self-inflicted gunshots, drug overdoses, or self-hangings are included here.



Homicidal: Death by the hand of another. 



Undetermined or Unclassified: Used when the coroner can’t accurately determine the manner of death.

These classifications are critically important since the official manner of death will determine what follows. In natural, accidental, and suicidal deaths, the police are rarely involved. Perhaps in the case of an industrial accident or if an insurance policy won’t pay in the case of a suicidal death, the police might be called in to investigate the situation further. But, in the end, if the coroner decides that the death falls into one of these categories, the police will not open a true investigation. In fact, in most such cases, they legally can’t do much. 

But, if the coroner concludes that the manner of death is homicidal, or if he is unsure, the entire spectrum of police investigative techniques might be employed. Or not. Police investigations get corrupted, botched, or simply ignored for various reasons. This is fertile soil for the crime writer.

What about this undetermined category? Can’t the coroner always uncover the manner of death? Unfortunately no. Real life is often untidy.


Run To GroundLet’s say a known drug addict is found dead in an alley with a needle in his arm and the coroner finds that the cause of death is a heroin overdose. What would be the manner of death? We can rule out natural since a heroin overdose is not a natural event. If the victim accidentally gave himself too large a dose, then the manner of his death would be an accidental overdose. Happens all too often. Or what if he has had enough of his miserable existence, no family, no friends, no future, and decides to inject himself with a massive dose? Here we have a suicide. But, what if the user is a snitch and his dealer knows about it. What if the next dime bag he gets is 90% heroin and not the typical 15%. He’s not a chemist. He only knows to cook up a certain amount and inject it. Here, the dose would be six times his usual. Roll the credits.

Heroin is a narcotic with very powerful sedative and what we call Central Nervous System (CNS) depressive effects. This means it will put you to sleep and suppress your drive to breathe. Too much and you will quickly lapse into a coma, stop breathing, and die from asphyxia.

At autopsy the coroner would see a dead guy with a boatload of heroin in his system and conclude that the cause of death was a heroin overdose. But, that’s all he could say. The manner of death would depend on who gave him the heroin and for what purpose. That’s where police investigation comes in. The results of this investigation will then guide the coroner in his determination of the manner of death. 

This where storytelling enters the picture. Your sleuth will give the coroner the information he needs to make the correct call.

In the next column, I will discuss various observations and tests that medical examiners use to determine time of death. Among those tests and observations are checking the victim’s body temperature, the contents of their stomachs, rigor mortis and insect activity.

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DP LyleD. P. Lyle is the Macavity and Benjamin Franklin Silver Award winning and Edgar, Agatha, Anthony, Scribe, and USA Best Book Award nominated author of many non-fiction books (Murder & MayhemForensics For DummiesForensics & FictionMore Forensics & FictionHowdunnit: Forensics; and ABA Fundamentals: Understanding Forensic Science) as well as numerous works of fiction, including the Samantha Cody thriller series (Devil’s PlaygroundDouble Blind, and Original Sin); the Dub Walker Thriller series (Stress FractureHot Lights, Cold Steel, and Run To Ground); and the Royal Pains media tie-in novels (Royal Pains: First, Do No Harm and Royal Pains: Sick Rich). His essay on Jules Verne’s The Mysterious Island appears in Thrillers: 100 Must Reads and his short story “Even Steven” in ITW’s anthology Thriller 3: Love Is Murder.

Along with Jan Burke, he is the co-host of Crime and Science Radio. He has worked with many novelists and with the writers of popular television shows such as Law & Order, CSI: Miami, Diagnosis Murder, Monk, Judging Amy, Peacemakers, Cold Case, House, Medium, Women’s Murder Club, 1-800-Missing, The Glades, and Pretty Little Liars.

Visit D.P. Lyle’s: Website  |  Blog  |  Crime and Science Radio

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