The other night I had a long phone conversation with my good friend Dr. Cyril Wecht and was able to pick his brain on several interesting forensic topics of interest to writers. Dr. Wecht is an internationally renowned forensic pathologist who has published extensively and has been involved in some of the most famous, and infamous, cases in the history of modern criminal justice. Cases such as: JFK, RFK, MLK and James Earl Ray, Elvis, Marilyn, O.J., Tammy Wynette, Sunny von Bulow, Lacy Peterson, Stacy Peterson, Anna Nicole Smith, Mary Jo Kopechne, JonBenet Ramsey, Vince Foster, Ron Brown, Kurt Cobain, and the infamous Manson Family Tate-Labianca murders, just to name a few. Dr. Wecht graciously consented to answer my questions.
DPL: How many autopsies have you performed in your career?
CW: If you go back to 1957 when I started my residency…what is that?…52 years?…then I have performed over 16,000 postmortem examinations myself and consulted on another 36,000.
DPL: That’s an amazing number. The most common question writers ask me is: Is there an untraceable poison or at least some that are very difficult to uncover by autopsy and toxicological examinations?
CW: This is an excellent question and one that vexes forensic pathologists around the world. I would say that the two most common circumstances where a poison is not found are when the toxin used is outside the experience of the examiner or when the toxin is something that is normally found in the body or would expected to be there.
The first category would include exotic poisons such as those from spiders and snakes and other exotic creatures. These aren’t searched for simply because no one ever thinks to. I mean, if you have a corpse and you’re looking for a cause of death, why would you think to search for the toxin of a Japanese blow-fish or a rare African snake? And if you don’t think of it you won’t search for it. None of these turn up on routine toxicological screens so they have to be searched for specifically.
The other category are things that are normally present or would be expected to be found in the body of the victim. Potassium chloride (KCl) is a normal constituent of our blood and cells. It is also very deadly. It is the third drug used in the three drug lethal injection death penalty scenario. An injection of potassium chloride intravenously will cause virtually instantaneous death and the potassium after death is essentially untraceable. It’s supposed to be there. Insulin in a diabetic is a similar situation. Even if elevated insulin levels are found at autopsy, it could easily be attributed to an accidental overdose. Diabetics do this all too frequently. Or what about the cardiac patient who is taking digitalis? An excess amount of digitalis can cause cardiac arrhythmias and death. But finding an elevated digitalis level in the victim’s blood could easily be construed as a medication accident and the thought that a homicide had occurred might never enter the examiner’s mind.
DPL: Are there any poisons that leave behind visible clues?
CW: Very few. Cyanide can turn the blood and the internal organs bright red but this is often more subtle than you might think and can easily be overlooked. Carbon tetrachloride, which is extremely toxic to the liver, can cause visible changes in the liver though most of these are seen when microscopic examinations are done. Here you see what we call fatty filtration of the liver. Ethylene glycol, the major component of most antifreeze products, causes the precipitation of oxalate crystals in the kidneys. These can be seen with microscopic examination, which of course is part of the autopsy examination.
Those are a few of the acute poisons that might leave behind obvious physical clues. There are many others that if given repeatedly can cause chronic changes in the body that can be seen visibly or with microscopic examination.
DPL: What toxins can be found with hair examination?
CW: The simple answer is that almost anything that is taken over a period of time can be found in the hair. What I mean is that a single dose of a chemical that is rapidly metabolized or quickly excreted from the body will not show up, but anything that has been taken over many days or weeks might. The classic example of course is arsenic and the other heavy metals. Other things like thallium, GHB, and sedatives such as Librium or Xanax or narcotics such as Fentanyl can often be found in hair samples.
Another important thing about hair is that it can often offer a general guideline for exposure. We will take the hair and cut it into very small segments and analyze each segment. Those that contain the toxin were the ones that were growing out of the hair follicle at the time the toxin was present and those that have less will be in times of reduced or absent exposure. This way we can tell that the victim was exposed to the toxin intermittently and can develop a general timeline for when this exposure occurred. If a particular individual was around him only during those times then this can be very strong evidence that the individual was involved in the poisoning.
DPL: You’ve obviously been involved in many famous and high profile cases, but is there a case that stands out as particularly unique, or odd, or satisfying?
CW: There have been so many it is difficult to select just one but the one that comes to mind is that of Robert Curley. I discussed this case extensively in my book Mortal Evidence. This case involved the issue that we were just talking about, that is, hair analysis to uncover a poison. In this case the chemical used was thallium, and it was administered by his wife for financial gain from an insurance company. The interesting part was that Mr. Curley’s hair was long enough that we were able to plot out the final 329 days of his life. The hair shafts were tested using atomic absorption spectrophotometry. The results indicated that he was poisoned over a nine-month period with peaks and valleys in the level of thallium in his hair, indicating intermittent exposure over that time period. The poison was also found in his fingernails and toenails and in several thermos bottles that he used to take tea to work. Apparently his wife had been spiking his tea with Thallium.
DPL: Thank you so much for answering my questions. I’m sure this will give my writer friends a lot to think about–and plot.
CW: My pleasure.
To learn more about Dr. Wecht and his many useful books visit his website.
To read about Dr. Wecht and his many famous cases visit the TruTV Crime Library: