She Had To Die Sometime

August 31, 2006 12:14 PM

Forensic question about murder, time of death, and... more inside...

(Note from Corky - I'm posting this for The Boyfriend™)

I am an aspiring mystery writer, working on a novel. A plot point key to the story involves a killer needing to establish as well as possible a time of death earlier than the actual, to create an air-tight alibi. The killer is a medical professional, so what he’ll do goes beyond keeping the body warm or other relatively simple procedures. He knows the police will check stomach contents for digestion of the most recent meal; is there some way he can speed up the metabolism of his victim? (He has access to her for several hours before he kills her.) Or is there another effective way to thwart the usual forensic tests?

posted by Corky to Law & Government (29 answers total)

Well, being hyperthyroid in general speeds up the metabolism. Just brainstorming here, but I wonder if a megadose of thyroid hormone (i.e., Synthroid or levoxyl) would do something like that? Perhaps one of our resident docs could weigh in to say. (If not, you could ask an endocrinologist.)
posted by scody at 12:22 PM on August 31, 2006

But they might show up in toxicology tests.
posted by thirteenkiller at 12:31 PM on August 31, 2006

I'm going to bookmark this thread, just in case Corky turns up dead and her boyfriend has an apparently airtight alibi.
posted by Lame_username at 12:36 PM on August 31, 2006 [2 favorites]

But they might show up in toxicology tests.

Thryoid hormone and thyroid-stimulating hormone (TSH, the standard marker for whether someone is hyper- or hypo-thryoid) is present in all humans, so I would guess it's not a part of a regular toxicology panel.

Additionally, high amounts of thyroid hormone actually cause TSH to go down (the lower your TSH, the more hyperthyroid you are), so even if they do look for TSH, all they would find is a low number -- which isn't, in and of itself, uncommon (I have to keep my TSH extremely low in order to keep my thyroid cancer in remission, for example).
posted by scody at 12:41 PM on August 31, 2006

Keep in mind that any procedure that he uses to achieve this which capitalizes on his resources or as a medical professional makes him look just as suspicious (ie: access to thyroid hormone [although that's a pretty interesting idea]). It had better be pretty cleverly disguised.
posted by hermitosis at 12:41 PM on August 31, 2006

IAA(former) forensic professional. thirteenkiller is right. Any questionable death would get full tox.

Re: stomach contents. Pump pre-digested meal into her stomach, obviously. But in my experience stomach contents are used more for looking for a source of choking, poisoning etc. than establinshing time since death.

Re: warmth. Heat is really only effective at speeding the taphonomy process once full-on putrefaction sets in. You're talking about someone who's discovered within a day of death, if the matter of an hour's worth of meal digestion matters for establishing an alibi. If she's discovered soon after death my guess is turning up the heating wouldn't be very effective in confounding PMI. As a matter of fact, depending on the source of heat, it could 'cook' the tissue and rather effectively preserve evidence you might want to destroy.
posted by methylsalicylate at 12:47 PM on August 31, 2006

Also, possibly indespensible to pros as well as writers: Estimation of Time Since Death in the Early Postmortem Period might give you some ideas of how to do it, or at the least, what to avoid. Forensic Taphonomy is good for an overview of the long-term decomposition process, and forensic techniques for establishing PMI.
posted by methylsalicylate at 12:52 PM on August 31, 2006

Response by poster: methyl... would pumping her stomach first, then adding pre-digested food stump the ME? Would there be any evidence of stomach-pumping found in investigation?

The killer needs to have ToD be determined as some four hours earlier, when he is very visibly someplace else.
posted by Corky at 12:54 PM on August 31, 2006

Well, if the killer's with her for a while beforehand... make sure she didn't eat anything (i.e. watch her timings and habits), then force-feed her before she dies. An examiner would notice any signs of forcing, but if she's bulimic they could be attributed that way. But seriously Corky, I think you're barking up the wrong tree with stomach contents.
posted by methylsalicylate at 12:56 PM on August 31, 2006

Also, if you want to discuss further, I'm my user name at yahoo. I have the texts (and not a few old cases) at my fingertips.
posted by methylsalicylate at 12:57 PM on August 31, 2006

Keep the body slowly rotating after death to avoid blood settling!
posted by thirteenkiller at 1:00 PM on August 31, 2006

Response by poster: methyl... you rock! And, you are very generous.

Expect email contact from The Boyfriend™, who is in awe of the power of The Hive Mind.

lame_username... no worries about my eminent demise. I'm safe as long as I am a good research assistant!
posted by Corky at 1:03 PM on August 31, 2006

Well, this may seem really (really) disgusting, but how about this:

The killer eats a meal, waits for the required amount of time, induces vomiting in himself, stores the semi-digested stomach contents, then intubates the victim (either pre or post mortem) to 'deposit' the evidence using a pump. This hinges on the question of when the person conducting the autopsy examines the stomach contents for signs of digestion, they are actually asking who did the digesting.

Actually, this might lead to a plot strand: how, the glamorous coroner asks herself, did this bruising occur, a few hours after the apparent time of death?
posted by veedubya at 1:04 PM on August 31, 2006

You'll likely also need some carefully pre-hatched fly larvae, to add that extra je ne sais quoi.
posted by CunningLinguist at 1:12 PM on August 31, 2006

is there another effective way to thwart the usual forensic tests?

Make sure there's nothing to test in the first place. Ask Scarabic about it.
posted by CunningLinguist at 1:13 PM on August 31, 2006

This reminds me of a Harriet Vane mystery I watched a few months ago (Have His Carcase) *spoiler alert* where the murderer had an airtight alibi (he thought) for the time of death. Problem was that since the victim was a hemophiliac, the time of death was different that he thought it would be. I think that's how it went, it may have been because he was a hemophiliac, it seemed that he died later than he actually did since the blood didn't clot. Anyway, the gist of it was, he had planned an alibi for the wrong time.
posted by witchstone at 1:15 PM on August 31, 2006

Corky says:

I'm safe as long as I am a good research assistant!

It would be terribly cruel to make you plan your own murder.
posted by Lame_username at 1:46 PM on August 31, 2006 [2 favorites]

This reminds me of a Harriet Vane mystery I watched

WATCHED?? HARRIET VANE???? It is a Lord Peter Winsey mystery and was written by Dorothy Sayles. Get thee to a bookstore and plunk down the 7.99. It's freakin fantastic.
posted by dame at 1:52 PM on August 31, 2006

Oh, I and forgot to say, yeah, look for a disease problem.
posted by dame at 1:55 PM on August 31, 2006

It would be terribly cruel to make you plan your own murder.

*writes brilliant idea down*

It's mine, bitches!
posted by scody at 2:00 PM on August 31, 2006

dame: To you it's Lord Peter Wimsey, to me it's Harriet Vane. She does discover the body, you know ;)
And I know they're all books, but the BBC series is REALLY good.
/derail
posted by witchstone at 2:06 PM on August 31, 2006

I know; I actually wanted to put the fact that one could read the example out there. I just chose the flabbergasted route.

But really? Harriet Vane? Totally lame author fantasy fulfillment. Vomit.
posted by dame at 2:12 PM on August 31, 2006

WATCHED?? HARRIET VANE???? It is a Lord Peter Winsey mystery and was written by Dorothy Sayles

Sayers. Dorothy Sayers.
posted by dersins at 2:28 PM on August 31, 2006

Here's an online Time-of-Death calculator:

http://www.pathguy.com/TimeDead.htm

I think time of death usually has a window of several hours, so you may want to make sure your the character's alibi covers that.

Could have the murder create secondary clues that would mislead investigators as to the time of death? Like electrocuting them in the bathtub, which blows a fuse stopping a flip-style alarm clock, which the killer cleverly set back four hours.
posted by justkevin at 3:00 PM on August 31, 2006

Okay. There are several ways in which time of death are estimated. Note: these gives estimates for time of death, not exact times, so if it is a matter of, let's say, 30 minutes difference between estimated time of death and his alibi, these won't help.

#1. Body temperature. Usually the ambient temperature is cooler than 98.6 F and the body cools. If let's say, she is out in the snow, have the murderer rig something to keep her body warm for a bit. Or make it look like she died in the snow when she really died elsewhere. Then her still high body temperature would make her look recently deceased.

#2. Stomach contents. The stomach empties into the intestines fairly quickly, let's say about two hours. So if there is food still in the stomach death occurred within two hours. Several ways to fake this. Have her eat a specific and unlikely meal in front of a group of people six hours before she is murdered. Then have the murder cajole (or whatever) to get her eat some of the same shortly before she is murdered. The conclusion will be that she was killed about the time of her previous meal.

#3. Lividity. This is the pooling of blood to one part of the body via gravity. The blood will stick there and after a time not blanch to the touch. To prevent this she needs to be rotated at least once.

#4. Insects. Some good ideas were suggested above. Certain insects do not attack after death (mosquitos). Other insects only attack after death (maggots). Some insects lay live larvae. Others lay eggs that need to be hatched first. If you stick larvae from insects that have to be hatched to the body, you will push back the estimated time of the murder.

There are a lot of other devices used to the point of cliche in mysteries. (although you might have a fresh twist on them) The broken watch. The call for help that wasn't really from the victim or wasn't made at the time of death. Maybe some of her blood in a car that makes it look like she was murdered at an earlier time, meanwhile she is being naively led around by her killer (and presumably out of sight of witnesses).

The thyroxine idea - I don't see how that would work. Thyroxine won't speed up her metabolism after she's dead or change the rate of post mortem events.
posted by dances_with_sneetches at 5:18 PM on August 31, 2006

Can you find a way to get the victim on Reglan?
posted by puddinghead at 7:46 PM on August 31, 2006

Ha ha, that always happens when you're making fun of someone else.
posted by dame at 6:41 AM on September 1, 2006

OK. I do this for a living.

Realistically, these things are all very imprecise. Lividity, rigor, temperature, animal activity, insects, etc are all affected by the environment the corpse was left in. It always smacks of frank amateurism when anyone does anything fictionally with these. Anyone narrowing time of death down to under a twelve hour window is automatically dismissed as complete bullshit. You just can't tell forensically. In the real world, most of these questions are answered for the forensic pathologist by their field (scene) investigators. Usually time of death is approximated by the 'last seen alive' approach

Stomach contents are used for one (possibly) two things. It's all toxicology. In a real medical examiner's morgue, stomach contents are measured, described (color, food bits, smell of alcohol, pills), and saved for the tox lab. That is it. Only rarely will the specific type of food be noted. Usually you just cannot tell.

The quickest decomposition cases I've seen are people who have died from sepsis in a hot, running shower. They can show early decompositional changes within 8-12 hours. And by early changes, I'm specifically referring to the 'marbling' phenomenon. Marbling is the changes that the blood in your very superficial veins undergoes as it is acted upon by bacteria who have colonized your bloodstream postmortem.

I don't have any great ideas for you to speed up a dead person's metabolism. Nothing believable at any rate. You could have the victim injected with bacteria before death, and then put into a hot environment. Speed up the decomp process.
posted by i_am_a_Jedi at 3:11 PM on September 1, 2006

I think Jedi's post may be a bit misleading or off. Narrowing down within a twelve hour window is complete bullshit? I suppose if the death was a time back. But body temperature can be used to get a good estimate, for example, if the body is still near natural physiological temperature in a place where it should cool. A 96 degree body in a 32 degree environ will be presumed to be recently deceased. Decomposing to warmth just won't make up for that.
I doubt you will find any medical examiner who would say it is complete bullshit to define TOD within a twelve hour window in all circumstances.
posted by dances_with_sneetches at 10:28 AM on September 4, 2006