Category Archives: Time of Death

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


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.


Crime & Science Radio: The Body Tells the Tale: DP Lyle and Jan Burke Interview Dr. Bill Bass and Jon Jefferson

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The Body Tells the Tale: DP Lyle and Jan Burke Interview Dr. Bill Bass and Jon Jefferson

Join DP Lyle and Jan Burke as they explore the world of death, corpses, and decay with Dr. Bill Bass and Jon Jefferson. Dr. Bass is the founder of the University of Tennessee Anthropological Research Facility, the so called Body Farm. Jon Jefferson is a journalist, writer, and documentary film maker. Together they write fiction as Jefferson Bass. This will be a lively, or is it deadly, interview.



The Body Farm-Wikipedia:

Tour The Body Farm:

Video Tour of The Body Farm:

WBIR Interview:

JeffersonBass Website:

Death’s Acre: Inside the Legendary Forensic Lab the Body Farm Where the Dead Do Tell Tales:

Metro Pulse: The Cult of Forensics Expert Dr. Bill Bass:

Peter Breslow’s 2004 NPR Profile of The Body Farm:



Bloodstain Camera Finds Blood Quickly and Efficiently

Detecting blood at a crime scene is often essential for determining if a crime did indeed occur and how the act unfolded—crime scene reconstruction. At the scene, a meticulous search for blood can be tedious, time-consuming, and eat up many man-hours.


Techs search for bloodstains

Techs search for bloodstains


Shed blood is not always obvious. The stains are not always patent (visible) but rather latent (invisible). The standard in such situations has been to employ Luminol, which can find even very small latent bloodstains. But Luminol takes time and requires darkness—not always obtainable, particularly in outdoor, daytime crime scenes.


Luminol helps expose latent bloody shoeprints

Luminol helps expose latent bloody shoeprints


A new technology developed by Dr. Meez Islam and colleagues at Teeside University promises to not only be able to detect latent blood spatters quickly but also age the blood very accurately. With month-old stains the device, which uses hyperspectral imaging, can narrow its deposition down to a day and with fresh blood down to an hour. This should greatly help with Time of Death determination—-or at least the time when the blood was shed.


Fresh blood spatter

Fresh blood spatter


Blood exits the body bright red but with time and oxidation becomes rusty brown and does so along a predictable timeline. Accurate determination of the bloodstain’s color with hyperspectral imaging reveals its approximate age.

Very cool. And potentially very useful.


Q and A: Can My Villain “Force Feed” Pills To a Dead Woman?

Q: My hero, an investigative journalist, is looking into the death of a woman at an acid house/rave party in the early 1990′s. The novel is set in the present day and so the hero has no access to the body, just autopsy reports, coroners reports, the transcript of the inquest, etc. The woman was a light user of Ecstasy but the autopsy discovered that she had 70 ecstasy pills in her stomach. The scenario I want to create is that the hero discovers that while the woman took some of the pills willingly, she was then force fed others, and then after she died she was force fed yet more. In order for this scenario to work I’m wondering the following:

1) For how long after death does stomach acid continue to operate?

2) For how long after death would the digestive system continue to break down the ecstasy and would the ecstasy continue to be absorbed into the bloodstream?

3) Is it likely/possible that a sizeable amount of pills would remain undigested in her stomach, bearing in mind that the body was not found for a number of hours?

4) What injuries/signs on the body would there be of someone force feeding her the pills?

5) Is it possible to force feed somebody pills after death, how would they get the corpse to “swallow” and what injuries might be caused to the body as a result?

James, St Albans, UK.





A: At death, all metabolic processes cease immediately since there is no longer blood flow to keep these processes going or even to keep the tissues and cells responsible for these activities alive. This includes the digestive processes. Sure there could still be a small amount of acid effect but this would only be from the acid in the stomach at the time of death and this would be quickly neutralized by the materials the acid was combining with. The bottom line is that all digestive processes cease immediately on death, more or less freezing the stomach contents in time. This is also true for the level of most toxins in the blood and urine, which offers the medical examiner a tool for determining the cause and time of death.

At death, the stomach would no longer move or churn or secrete acids and digestive enzymes so the ecstasy would remain intact as it was at the time of death. Yes there could conceivably be residual whole pills and in fact this is not uncommon in overdoses of all kinds. Some dissolve and are absorbed prior to death and others do not and these remnants can then be tested to determine what they are. All the stomach contents would remain intact until the decay process destroyed them, so if the body was found in a reasonable period of time, the stomach contents could be analyzed for their chemical characteristics, which would include the presence of any drugs or alcohol.

It is very difficult to force-feed a living person pills and so doing could lead to trauma around the mouth and face as the pills were shoved into the victim’s mouth and his mouth and nose held close until he swallowed. Or there could be no trauma and in which case there would be no way of knowing this. But evidence of trauma might suggest a force-feeding. It would be a best guess but an experienced medical examiner can usually make this determination. Since all processes and movement by the deceased stop at death, swallowing cannot occur and force-feeding a corpse is impossible. The pills would simply collect in the mouth and throat.

In your victim there could easily be undigested pills and toxicological testing of these, and of course blood and urine, would reveal what chemicals were in the victim’s stomach and system. Since your body is found several hours later there would be essentially no decay and therefore everything in the bloodstream and in the stomach would remain intact more or less as it was at the time of death. With facial trauma the ME might consider that the OD was forced, and in the absence of such evidence might simply think it was an intentional or accidental OD.

Also this ARTICLE on my website might help.


Q and A: Can My ME Determine If a Child Died From Exposure As Opposed To Being Locked in a Heated Vehicle?

Q: In my story, a police officer is on the scene where the body of a 3 year old child was found among the rocks and weeds of a dried up riverbed in Southern California. It is early summer. Can the CSI techs or the ME determine if the child died from being locked up in a heated car rather than from exposure to the elements where the body was found?

Jack Dietz, Production Coordinator, Las Vegas, NV

A: The simple answer is that this is not very likely however there might be a way. Much depends on the condition of the body. If it is severely decayed or has become skeletal, the ME would have little to work with and there would be no way to determine exactly where the death occurred. In either case the death would be from that catchall term “exposure.” What that means is that the victim died from lack of water or food, with water of course being the most important. Exposure deaths are almost always due to severe dehydration.

However, if the child is found within a day or two of death, the body would be more or less intact and the ME might be able to estimate where the death had occurred, given the two choices you outlined. One difference would be insect activity. If the child died in the trunk as opposed to being exposed outdoors there would be less insect activity for the amount of time since death than would be expected from an exposed corpse. If the ME determined that the child had been dead for 2 or 3 days yet there was essentially no insect activity, it would mean that she had been in a protected environment, such as an enclosed car or car trunk, for those 2 or 3 days and only exposed for maybe a few hours. On the other hand, if he found insect activity that matched his estimate of the time since death, this would favor her being in an exposed environment for those 2 to 3 days. It’s not that flies can’t get into car trunks, it’s just that most trunks are so well sealed, fly access would be very limited, if at all.

On a similar note, predatory animals would not be able to attack the body while it was in the car but if exposed predator feeding on an exposed body is fairly common. Coyotes are everywhere. Predator activity would suggest a longer period of environmental exposure.



One circumstance that might be interesting for you would be if the child died in either the trunk or on the floorboard of the car. As she died from hyperthermia and dehydration, she would increasingly gasp for breath toward the end of her life and could inhale carpet fibers from the trunk lining or floor carpets. This would not happen if death occurred while exposed outside. This would of course require that the body be in fairly good condition. I think as long as you have the body found within a few days, the decay process would not have progressed far enough for the lungs to be destroyed and the medical examiner might see these fibers during his microscopic examination of lung tissue. Once he found these fibers, he would know that the victim had inhaled them and therefore was alive while in the car. So finding the fibers would at least allow the medical examiner to guess that she had been in the car near or shortly before her death.



Another interesting thing about this scenario is that the ME could then analyze these fibers physically, optically, and chemically and determine the manufacturer of the carpet and this in turn could lead to the car manufacturer and even the make and model year–or at least a narrow range of years since car manufacturers change their products quite frequently. This would greatly help your police officer develop suspects.



Q and A: Can My ME Distinguish Death From Asphyxia From Death Due to Head Trauma?

Q: Here’s my book situation: A man puts a plastic bag over his head to kill himself. His wife wakes up next to him (after he nearly strangled her to death and she discovers he’s killed their son) and in her horror and rage cracks him over the head with a blunt object.

Here’s my question: Can the police/coroner/forensics determine which was the cause of death–suffocation or blunt force trauma? If so, what would the signs be pointing to asphyxiation?  Also, if it matters, this is set in 1969.

Judy Merrill Larsen, author of All the Numbers

A: If the victim died first from the asphyxia, the ME would have no problem since the blow to the head would cause no bruising or bleeding. At death the heart stops and blood flow ceases and a corpse will not bleed or bruise easily. So the ME would see a mark where the victim was struck but no bleeding or bruising and know that the blow was delivered post-mortem.

If he was still alive when struck, things become a little more difficult for the ME but he should still be able to tell. Bruising and bleeding at the site of the blunt trauma would show that the victim was alive when struck but if there is no significant brain injury found at autopsy he would know that the force of the blow did not cause death and the asphyxia must have. If there is a brain injury such as cerebral contusion (brain bruise) or bleeding into or around the brain, he might have difficulty determining the actual cause of death. Of course any evidence of blunt trauma would point to homicide and not suicide since someone using a plastic bag for suicide would not likely also strike themselves in the head.

But I see a bigger problem with your scenario. If she was unconscious from being strangled, she would wake up within 10 seconds to a minute or so after the pressure was released unless she had significant brain injury from lack of oxygen. If she were simply strangled into unconsciousness, which is due to blocking blood flow thru the carotid arteries to the brain and not blocking breathing, as soon as the pressure was released and blood flow reestablished, she would wake up very quickly. Much sooner than he could put a bag on his head and die from asphyxia. For her to be out that long would require some degree of brain injury and I don’t think that’s what you want. Of course, if he drugged her first and then strangled her to the point he thought she was dead, but she in fact wasn’t, then she would awaken when the drug effect wore off. Here he could be dead for hours before she awakened.



Q and A: Can My Serial Killer Make His Victims Float Face-up?

Q: My serial killer has predilections that make him want his (female) victims to float face up when they are found. He strangles them and then places them in the water, so they don’t actually die of drowning. Would plugging the throat or taping the mouth and nose shut (so air stays in the lungs) be a good way for him to achieve this effect? What else might work?

S.K. Davenport, Pittsburgh, PA

A: Plugging the throat or taping the mouth and nose would make little difference since there is not enough air in the lungs to cause a body to float. Virtually all bodies sink when first tossed into water. This is not absolutely universal as sometimes clothing can gather air and keep the victim afloat but for the most part they sink. They do not float again until the decay process has progressed to the point that gases have collected within the abdomen and the tissues and the body becomes buoyant. Most bodies float facedown for a very simple reason–the arms and the legs tend to fall in that direction rather than backwards so their weight keeps the body face down.

In order to make the body float he would have to do something to increase the rate of decay and since this is predominantly temperature dependent it would be best if the body was placed in warm water such as a heated pool, a Jacuzzi, or a swamp in Louisiana. Alternatively–and this is over-the-top sinister–he could inject air into the victims abdomen and chest and even the tissues of the legs and arms. If he injected enough the body would float immediately. In order to keep the body on its back, he would have to apply weights of some type that would weigh down the backside of the corpse. Maybe some large fishhooks placed deeply into the flesh and muscles with weights attached. Just a diabolical thought.


Posted by on January 4, 2013 in Asphyxia, Crime Scene, Q&A, Time of Death


Q and A: If a Corpse Has Undergone Adipocere Formation, Can My ME Accurately Determine the Time of Death?

Q: In your blog you have talked about the formation of adipocere and explained the process. But what about how to estimate the time of death after a corpse has gone through the process of saponification? In my current project I have a body covered in adipocere. The victim is found 15 years after she was killed. Will it be possible for the detectives to determine exactly when she had been killed?

EE Giorgi, Los Alamos, NM

A: The short answer is no they would not be able to. At least not from the adipocere alone.

Adipocere formation is not common but it does indeed occur. This process is not one where the body is covered with adipocere but rather the body turns into this soap-like material. This can happen in a few weeks under the proper circumstances, which is usually a body buried in very acidic or alkaline environments. But it can happen under many circumstances.


Once it is formed the body remains fairly stable and can easily remain intact for 15 years or longer. But there is nothing about the adipocere itself that would give a timeline for when death occurred. Based only on that it could’ve been a few months ago or a few decades ago and the medical examiner has no tools for really distinguishing one from the other.

He would instead rely on other information such as when the person went missing. Let’s say the victim was 20 years old at the time of death. That would mean she would be 35 at the time the body was found. When the medical examiner, and perhaps a forensic anthropologist, examined the body they would know that the corpse was more consistent with someone in the 15 to 20 year old range than someone in the 35 to 40 year range and therefore could say that she had been dead for 15 years or so.

There might also be scene markers such as the clothing she was wearing or items found in her pockets, purse, or anything else found at the burial site. Some of these might suggest that she died shortly after she disappeared. Maybe a friend had just given her a check or a letter to mail and it had somehow survived in her purse. Most people deposit checks and post letters fairly soon rather than keeping them in their possession for weeks or months. So if these were found it would suggest she had died fairly soon after receiving them.

Maybe she was known to be wearing a certain shirt or jacket or other item of clothing at the time she disappeared and the same clothing was found on or around the corpse. This would be strong evidence that she died around the time she had disappeared simply because had she lived for a period of time after disappearance she would likely have changed clothes.

The ME could see all of this and make his best estimate that she probably died around the time she disappeared.


Sniffing Out the Time of Death

You’ve seen a paramecium before. It was that little football-shaped (actually a prolate spheroid) critter that you viewed under the microscope in high school biology class. These tiny creatures are covered with microscopic hair-like oars known as cilia, which they use to move around in water.


Similar cilia line your nose and airways. They help you remove inhaled dust and dirt from your lungs and nose. Apparently they continue moving, at a progressively slower rate, for up to 20 hours after death. Biagio Solaria and his colleagues at the University of Bari in Italy have studied this phenomenon and found that the this decline in mobility is predictable and observing the beating rate of cadaver cilia might provide an accurate time of death in the first 24 hours after death. They will report their results in the upcoming International Symposium on Advances in Legal Medicine in Frankfurt, Germany.

Since all methods for determining the time of death are fraught with inaccuracies, a new method is always welcome. Hopefully, this one will pan out.


Posted by on October 5, 2011 in General Forensics, Time of Death


How Old Is That Blood Stain?

Your detective is called because a body has been found dumped in a remote area. The victim is identified as a man who has been missing for four months and the medical examiner determines that his death likely occurred around the time of his disappearance. He had been in a dispute with a business partner over ownership of their company. The business partner has always maintained that the victim sold out and moved away to parts unknown. A fishy story but your detective has little to go on.

The search warrant is executed on the business partner’s home and indeed an old bloodstain is found on the garage floor. Blood typing and DNA analysis proves that it is the victim’s blood but the partner says it was from two years earlier when the victim helped him move some furniture and injured his hand, bleeding on the floor. He said they both cleaned it up at that time but he must’ve missed a spot.

The dilemma facing your detective is how to determine when the blood was shed? Four months ago or two years ago? DNA will only tell him that the blood belongs to the victim but it will not tell him when it was deposited.

Enter Messenger Ribonucleic Acid (Messenger RNA or mRNA).

Our DNA is our instruction manual. It tells each cell of the body what to do and how to do it. But DNA is inert. It does nothing except hold information. The real work is done by the enzymes in the cytoplasm of the cell. They create new proteins, other enzymes, various chemicals, and all the other things required for life.

But how does the DNA pass its instructions out to the cytoplasm where the needed worker enzymes are created and ply their trade? By employing mRNA, a temporary molecule, that is synthesized within the nucleus according to the instructions coded within the DNA. The mRNA then migrates into the cell’s cytoplasm where it directs the creation of the enzymes needed to do the job. In effect it carries the DNA’s instruction to the workplace. That’s why it’s called messenger RNA. This is of course a simplified explanation of a very complex process.

So what does this have to do with the age of a blood stain? Anne-Marie Simard of the University of Montréal is studying the degradation of four messenger RNA molecules found within blood, saliva, and semen. Her preliminary findings suggest that these molecules degrade at a measurable rate and if this is proven to be true such studies might be useful for determining the age of crime scene samples.

This could be a very useful tool for homicide investigators, particularly in cases such as the fictional one I outlined above. Determining the blood stain was four months old rather than two years would require an explanation from the business partner.


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