Sunday, December 23, 2007

D.P. Lyle's "Forensics and Fiction"

D. P. Lyle, MD is the Macavity Award winning and Edgar Award nominated author of the non-fiction books Murder and Mayhem: A Doctor Answers Medical and Forensic Questions for Mystery Writers, a compilation of the most interesting questions he has received over the years, and Forensics For Dummies, an in depth look into the world of forensic science. His published fiction includes the thrillers Devil’s Playground and Double Blind.

He applied the "Page 99 Test" to his latest book, Forensics and Fiction: Clever, Intriguing, and Downright Odd Questions from Crime Writers, and reported the following:
I’m not sure that the Page 99 Rule holds for all books, but it seems to for Forensics and Fiction. This book is the follow up, or sequel, to my book Murder and Mayhem, which was also in the Q&A format. Both books are a compilation of the best questions I have received from novelists and screenwriters over the years. The question on page 99 of Forensics and Fiction from Paul Yuell, a staff writer for the TV series Cold Case, about with whether the coroner can determine the type of alcohol a deceased person might have consumed prior to death, is typical of the types of intriguing and clever questions that writers ask. Forensics and Fiction contains nearly 180 such questions. And even more, as well as forensic articles of interest to writers, can be found on my website, The Writers Medical and Forensic Lab at www.dplylemd.com.

The question that begins on Page 99:

Can the Type of Alcohol a Victim has Consumed Be Determined at Autopsy?

Q: I am working on a story in which someone drowns while being very intoxicated. Can a medical examiner determine how much and what kind of alcohol is present in a victim's blood? If the corpse is not found for eight hours will there still be alcohol in his blood or does it break down?
Paul Yeuell

Hollywood, California

Television writing staff, researcher, CBS's Cold Case

A: The short answer is, most likely.

If the victim had taken enough alcohol to cause intoxication, his tissues and stomach contents would reflect this. Since all metabolism (the breakdown of toxins and foods) ceases at death, the alcohol would not undergo any conversion by the body itself. At least, not enough for its level to decline appreciably. Toxicological testing for alcohol is done easily and highly accurate, so the ME could determine the exact level of the alcohol within the victim. In suspected alcohol-caused deaths, or in deaths where alcohol intoxication might be a factor, the ME can measure the alcohol level in the cadaver’s blood and urine (typically blood is used and is the most accurate determinant) and tell if the intoxication level was high enough to have caused or contributed to the death. In your scenario if he found a very high level of alcohol he might conclude that the intoxication was an important factor in the drowning. If he found a low level he might conclude the opposite---that alcohol had little or nothing to do with the drowning.


There are, whomever, a few situations where this testing may be inaccurate. If the body undergoes putrefaction (decay due to bacteria), and if this process is so far along (days or weeks, not eight hours) that the tissues are severely broken down, then the alcohol may also be consumed in this decay process to a degree that the ME can’t be sure what the pre-mortem level actually was. And with severe decay the alcohol level may actually increase due to the action of the putrefying bacteria, some of which produce alcohol as a by-product of their activity. Go figure.


To get around this, a determination of the alcohol level in the vitreous fluid of the eye would be done. This is the fluid within the eyeball, and it is called the vitreous humor — not as in funny but as in the old humors of Aristotle. Some things in medicine never die. The alcohol level in the vitreous humor reflects the blood alcohol level with a 1 to 2 hour lag. That is, it can tell the ME what the blood level was one to two hours before death, but not right at death. This allows him to make a “best guess” as to the level of intoxication at the time of death, and since this is all ballpark anyway, this estimation usually suffices.


In your scenario the ME would have a fairly intact corpse, since little decay would occur in only eight hours. He would test the blood, urine, stomach contents, and possibly the vitreous fluid, and uncover the type and amount of alcohol present.


Regarding the type of alcohol, he could determine that the alcohol was ethanol (drinking alcohol) as opposed to methanol (wood or denatured alcohol) or isopropanol (rubbing alcohol). But using blood, urine, or vitreous fluid, he could not tell what type of drinking alcohol was consumed. Ethanol is ethanol. Beer, wine, and whiskey all contain the same alcohol and all look the same in the blood. But if the stomach contents are analyzed it is at least possible that he could distinguish beer from wine from vodka. Not from the alcohol in these beverages but from the other chemicals that make wine wine and beer beer. Or he may not be able to determine this. It can go either way.

Read an excerpt from Forensics and Fiction, and learn more about the author and his work and writing at D.P. Lyle's website.

--Marshal Zeringue