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Category Archives: Time of Death

Muscle Proteins and the Time of Death

crime-scene

In any homicide, one the most important things, along with the cause and manner of death, that the ME must determine is the approximate time of death. This will help eliminate some suspects—-if they are far away from the scene and with many witnesses, for example—-and point the finger at others—-who might have been in the area at the time the murder occurred.

The problem is that most methods used to determine the time of death are inaccurate at best. They tend to be best guesses. And they are mostly useful only during the first 48 to 72 hours.

Check out my article “Timely Death” for a brief overview of how the time of death is estimated.

Or grab a copy of Forensics For Dummies or Howdunnit: Forensics for an in-depth discussion of this topic.

Researchers at the University of Salzburg are working in a new method that might allow the time of death determination to be accurately made up to 10 days after death. Their research suggests that measuring the rate of muscle protein degradation yields a clue to the time that has lapsed since death. If this technique proves to be accurate and reproducible in humans, it would be a giant step forward in criminal investigations.

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Crime and Science Radio: A Fly for the Prosecution: An Interview with Forensic Entomologist Dr. Lee Goff

Join Jan Burke and me as we discuss bugs and bodies with forensic entomologist Dr. M. Lee Goff.

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BIO: Dr. M. Lee Goff is one of the founding members of the American Board of Forensic Entomology, from which he retired in 2013.  Professor Emeritus, in Forensic Sciences at  Chaminade University of Hawaii and Dept. of Plant and Environmental Sciences, University of Hawaii, Manoa,, he received his B.S. in Zoology from the University of Hawaii at Manoa in 1966, M.S. in Biology from California State University, Long Beach in 1974, and Ph.D. in Entomology from the University of Hawaii at Manoa in 1977. He was Professor of Entomology and Chair of the Entomology Graduate Program at University of Hawaii at Manoa from 1983 until 2001. He then moved to Chaminade University of Honolulu as Director of the Forensic Sciences Program. Dr. Goff has been involved in forensic entomology for a period of over 25 years. He is currently a consultant in forensic entomology for the Office of the Medical Examiner, City and County of Honolulu and other state and federal agencies throughout the world.  He also serves as a consultant for the crime dramas CSI and Bones. He is curator of a traveling museum exhibition called CSI: Crime Scene Insects.

Additionally Dr. Goff has served as a member of the instructional staff for the FBI Academy course in Detection and Recovery of Human Remains taught at Quantico, Virginia. He has published over 200 papers in scientific journals, authored the popular book, A Fly for the Prosecution, co-edited the recent publication “Advances in Forensic Entomology” and participated in over 350 homicide investigations, consulting on cases worldwide.

LISTENhttp://www.blogtalkradio.com/suspensemagazine/2015/04/30/crime-and-science-radio-with-special-guest-dr-lee-goff

LINKS:

Professor Emeritus Goff’s faculty Page on Chaminade University’s site https://www.chaminade.edu/natural-sciences/faculty/M_Lee_Goff.php

PBS Nature‘s Crime Scene Creatures Interview: Forensic Entomologist Lee Goff http://www.pbs.org/wnet/nature/crime-scene-creatures-interview-forensic-entomologist-lee-goff/302/

Dr. Goff Interviewed on KHNL-TV https://www.youtube.com/watch?v=lnNe8SNAz08

National Geographic Channel 2004 Interview with Dr. Goff http://news.nationalgeographic.com/news/2004/04/0423_040423_tvbugman.html

American Board of Forensic Entomology http://www.forensicentomologist.org

Insects.org  http://www.insects.org

Acarological Society of America https://sites.google.com/site/acarologicalsociety/home

Acarology: The Study of Mites and Ticks (UK’s Natural History Museum) http://www.nhm.ac.uk/hosted-sites/acarology/

Entomological Society of America http://www.entsoc.org/home

Insect Collections, Zoos, Museums, and Butterfly Gardens in North America http://www.entsoc.org/resources/links/zoos

Amateur Entomologists’ Society: Forensic Entomology http://www.amentsoc.org/insects/insects-and-man/forensic-entomology.html

How Stuff Works: What do bugs have to do with forensic science? http://science.howstuffworks.com/forensic-entomology2.htm

Smithsonian Channel Catching Killers: Insect Evidence http://www.smithsonianchannel.com/shows/catching-killers/insect-evidence/1003122/141561

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Q and A: What Would My Victim of Scaphism Look Like After Two Weeks in a Pond?

Q: My question is what would a corpse be like, a victim of scaphism and encased in leather with only the head, hands and feet protruding, discovered after about two weeks in a stagnant pond in summer in England.

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Scaphism

 

A: This is a very complex situation which means that almost anything can happen. Particularly in face of your killer employing scaphism in your poor victim’s ordeal. There are many forces in this circumstance conspiring to destroy the body. After two weeks the decay process would be well along and the body should be swollen and discolored and there might already be some sloughing of tissues, particularly in the hands and the feet so that the fingernails and toenails might have slipped away. The leather binding might lessen the degree of abdominal swelling but maybe not.

Or the decay might be a little less and the body might appear only slightly swollen and discolored. Either is possible. When you add the insects and marine predators such as fish to the picture, tissue destruction could be significant—-or again very mild. Once the body floated or if it were placed on a wooden float of some sort, the insects would easily reach the corpse. These insects prefer warmer and moister areas so they tend to accumulate around the eyes, nose, mouth, groin, and any wounds such as an open abdomen or a stab wound.

Their activity could be significant or minimal, often depending on the weather. If it has rained a lot or if it is windy or if there has been a great deal of fog, insect activity would be diminished as insects do not like these conditions. But, i the weather was warm and sunny, they would be more active. Often when the medical examiner is determining the time of death in bodies that are several weeks old, he will consult a forensic climatologist to assess the weather effects in play and from this make his best guess as to insect activity and this in turn will tell him how long it took for the insects to reach the level of infestation seen. Again is always only his best estimate. And then you throw in predators, both marine and otherwise, and his problems multiply.

At the end of the day, your body would likely have a great deal of decay as described above as well as insect activity. The latter could be everywhere but would be particularly pronounced in the exposed areas where the tissues were easier for the insects to get to. Still they find their way beneath leather bindings and clothing and coverings in order to get to their next meal.

You have a great deal to work with here in that the body can either be slightly or severely decayed and the insect activity can be great or small and anywhere in between. The old adage is that whatever happens, happens. This actually gives you great leeway in how you construct your plot.

 

Can Odor Reveal the Time Of Death?

One of the most important determinations that the medical examiner must make in any death investigation is the Time Of Death (TOD). This alone might help solve a homicide. Who had the motive, means, and opportunity? The time of death relates to the opportunity. If the death occurred while the primary suspect was in another state or had a solid alibi, then he moves down the suspect list. On the other hand, if the TOD was determined to be a time frame where he was in the neighborhood, then he remains a viable suspect.

The ME uses many techniques to help estimate the TOD. Check out this ARTICLE for a brief overview of these techniques. One of the methods he employs is the degree of decay that has occurred. He must take into account the environmental conditions near the corpse and then must make a best estimate as to how fast the decomposition process would have advanced under those conditions. This is always a best guess, as is the case with each of the techniques he employs.

When a corpse decays it undergoes a chemical decomposition and this process releases many volatile organic compounds (VOCs) into the surrounding air. These compounds are at least partially responsible for the odor of decay and they tend to be released in a predictable pattern as the decay process progresses. What if these VOCs could be sampled and used as a more scientific method for determining the Post Mortem Interval (PMI)? That is, the time since death.

Research is currently underway to assess this technique. Using the combination of gas chromatography and mass spectrometry (GC/MS), researchers have found that these volatile chemicals can be trapped and analyzed. Hopefully this technique will prove to be useful in narrowing down the TOD. We’ll see.

 

Gas Chromatograph

Gas Chromatograph

 

 

 

Crime and Science Radio: Dealing With the Dead: A Life in the Morgue: In Conversation with Dr. Cyril Wecht

Join DP Lyle and Jan Burke as they welcome Dr. Cyril Wecht, internationally renowned forensics pathologist Dr. Cyril Wecht as we discuss his life in criminal justice and the numerous famous cases he has been involved with over his stellar career.

BIO: Dr. Cyril Wecht holds degrees in both medicine and law, receiving his MD degree from the University of Pittsburgh and his law degree from the University of Maryland. He holds professorships at the University of Pittsburgh and Duquesne University School of Law. He has published nearly 600 scientific articles, is on the editorial board of more that 20 medical-legal and forensic scientific publications, and had published several books on forensic science. His list of famous cases is a who’s who in medical-legal investigation.

 

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LISTEN: http://www.blogtalkradio.com/suspensemagazine/2014/03/07/crime-and-science-radio-with-special-guest-cyril-wecht-md

LINKS:

Dr. Wecht’s Website: http://www.cyrilwecht.com

Dr. Wecht’s books and videos: http://www.cyrilwecht.com/books.php

50 Years Later, Wecht Continues To Poke Holes in Report on JFK Assassination: http://triblive.com/news/allegheny/5017529-74/wecht-commission-specter#axzz2tuBTchS1

Dr. Cyril Wecht Believes Killers of JFK, RFK, MLK Had Help: http://www.vindy.com/news/2013/may/01/renowned-pathologist-makes-a-case-for-co/

Dr. Cyril Wecht Lectures on the JFK Assassination: https://www.youtube.com/watch?v=-muQL-QPKeM

Dr. Cyril Wecht on JFK Assassination: Let’s Uncover the Truth: https://www.youtube.com/watch?v=YtUL-BpZAu8

Crime Library: JonBenet: From Impressions To Book by Dr. Katherine Ramsland: http://www.crimelibrary.com/criminal_mind/forensics/cyril_wecht/6.html

Dr. Cyril Wecht Discusses Forensic Challenges of Cold Cases: http://www.wtae.com/news/local/allegheny/Dr-Cyril-Wecht-discusses-forensic-challenges-of-cold-cases/19648550

Dr. Cyril Wecht: The Benefits of Forensic Credentialing: http://www.pbs.org/wgbh/pages/frontline/criminal-justice/real-csi/dr-cyril-wecht-the-benefits-of-forensic-credentialing/

Cyril H. Wecht: What I Know: http://www.pittsburghquarterly.com/index.php/What-Do-I-Know/what-do-i-know-with-cyril-h-wecht.html

Dr. Cyril H. Wecht: Pittsburgh’s Polymath: http://www.popularpittsburgh.com/pittsburgh-info/pittsburgh-history/famous-pittsburghers/dr-cyril-wecht.aspx

 

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Bacteria and Time Of Death

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One of the most important things the ME must determine in any death investigation is the time of death. This determination can support or destroy alibis and suspect and witness statements, and point the finger at certain individuals while directing it away from others.

The ME uses various techniques to make his “best guess” as to the victim’s time of death. Things like body temperature, rigor mortis, lividity, stomach contents, and a few other determinations. Unfortunately, most of these are only marginally accurate.

Here is an article I wrote on this subject: http://www.dplylemd.com/DPLyleMD/Art-Timely_death.html

Any tool that can help make this assessment more accurate would be welcome.

Researchers at Sam Houston State University’s Department of Biological Sciences are looking into just such a tool. Bacteria. Just as insects visit a corpse in a more or less predictable pattern, it seems that bacteria do also.

We’ll see how this pans out but it’s very interesting.

 

 

Q and A: How Would the Time of Death Be Determined in a Corpse Found in Snow?

Q: In my story, the body of a young woman is found by cross-country skiers in high-mountain country. (Average temps in December: 20 degrees/low to 40 degrees/high;  elevation about 9000 ft.) If the person had been dressed in heavy clothes, and the body had been there about 24 hours, would it be completely frozen? Partially? Would there be any way to determine when death had occurred?

MT, Albuquerque, NM

Jack-Frozen

A: The corpse would be at least partially and could be completely frozen–perhaps with some of the deeper internal organs only partially frozen. It depends on the clothing, exposure, moisture, wind, etc. Also the old rule that whatever happens, happens comes into play here. So the freezing could be either complete or partial.

Under these conditions, rigor and lividity would be delayed to an unpredictable degree so these would be very crude indicators and not very useful in determining the time of death (TOD). Body temperature might be more useful—emphasis on might—but this would not be very accurate either. If the core body temp had reached the ambient temperature, this determination is of no use, since once the corpse reaches the ambient temperature it will remain stable at that temperature, making body temperature useless. For example, if the corpse reached the ambient temp after 18 hours then 24 hours would look like 36 or 48 as far as body temp is concerned.

But if the corpse hasn’t reached ambient temperature, core body temp can be used to estimate the TOD. Not very accurately but at least in the ballpark. Under “normal” circumstances, a body loses heat at about 1.5 degrees per hour, but this depends on many variables. Your scenario is definitely not “normal,” so temp would be lost more rapidly. Could be 2 or 3 or 4 degrees per hour if there is wind or cold rain for example. Let’s say the ME found the core temp was 40 with an ambient temp of 30. This means the body is still cooling since it has not yet reached ambient temperature. Let’s also say that in his experience he believes (educated guess at best) the body would lose about 3 degrees per hour under the circumstances he sees at the scene. If so, subtracting the measured corpse temperature (40 degrees) from the normal body temperature (98) and dividing by the rate of loss (3 degrees/hour) would yield the estimated TOD.

The math: 98-40 = 58; 58/3 = 19 hours.

Based on these calculations, your ME might conclude that the death occurred approximately 19 hours earlier, give or take a couple of hours.

Of course the major flaw here is that the actual rate of temperature loss might vary from his estimate so, despite the math, his assessment remains a best guess. He would likely suggest a broad range—maybe saying the TOD was between 16 and 24 hours earlier. That’s really the best he could do.

So your corpse could be partially or completely frozen and the time of death could be difficult to determine. Except for one more trick: stomach contents.

Let’s say the corpse is frozen so that temp, rigor, and lividity are of no help yet it was known that the victim had eaten a certain food at a certain time prior to his disappearance. It takes the stomach 2-3 or so hours to empty after a meal so if the ME found the undigested meal in the victim’s stomach and knew the time of this final meal from witnesses, he could then more accurately place the time of death as within 2-3 hours after that meal. Let’s say he had lunch around noon, went skiing, and was then found dead 24 hours later. If the ME found that last meal still in his stomach he might suggest that the TOD was between 1 and 4 p.m. the day before. This might be your best bet for narrowing down the TOD.

 
 
 
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