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

21 Feb

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

  1. Nancy DeMarco

    February 21, 2014 at 10:44 am

    Thank you! I have a body that’s been frozen for a couple months, and I was scratching my head over TOD. Now I’ll send her to the community supper right before she goes missing. Yippeeeee! :D

     
  2. Cheryl B. Dale

    February 21, 2014 at 3:51 pm

    Great info!

     
  3. E. J. Wagner

    February 22, 2014 at 9:56 am

    Doesn’t this presume death occurred at the site and wasn’t dumped from another location?
    And that stress didn’t affect the time of digestion?
    Just saying':)
    EJ

     
    • D.P. Lyle, MD

      February 22, 2014 at 10:02 am

      Sure. If the corpse had been elsewhere and then dumped in the snow it might not be frozen at all and might even still be warm so to speak— if so determining TOD from body temp would be more complex—the temp where the body lay before being dumped would be unknown. But the stomach contents would not be affected by this—unless severe decay had set in–but that’s opens up a whole other topic.

       

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