Searching for a body of evidence
15 Sep 2010 by Evoluted New Media
Dead bodies buried under patios are commonplace in soap storylines, but forensic scientists can find themselves searching for and recovering corpses in real life; it can be time consuming especially if you’re not entirely sure where to look, but a new tool may make this task easier.
Dead bodies buried under patios are commonplace in soap storylines, but forensic scientists can find themselves searching for and recovering corpses in real life; it can be time consuming especially if you’re not entirely sure where to look, but a new tool may make this task easier.
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Scientists develop new ways to detect decomposing corpse |
The tool – developed by chemists at NIST (National Institute of Standards and Technology) – detects biochemical changes in a decomposing corpse and is a modification of a technique to sense minute levels of hard-to-detect chemicals.
“We originally developed this method for the measurement of the headspace above explosives to facilitate the certification of devices such as those deployed in airport screening facilities,” Thomas J Bruno told Laboratory News, “Since it worked so well for trace constituents in real explosives (such as C4, Semtex, etc.) we subsequently applied it to detecting food spoilage, by sensing decomposition markers in poultry. We were prompted to apply it to gravesoil after attending presentations at the American Academy of Forensic Sciences, where we learned how difficult this can be.”
The process uses an alumina-coated, porous layer, open tubular (PLOT) column with a motorised pipette that pulls in air samples at ambient temperatures to detect ninhydrin-reactive nitrogen (NRN) in the vapour phase which has collected in air pockets above and close to gravesoil.
“The device can be used to detect a body buried under a concrete slab, merely by drilling one-eighth-inch hols and inserting the probe, thereby eliminating the need for unnecessary digging,” said Bruno. “The device effectively and quantitatively traps the compounds of interest, even at trace levels, and facilitates the transfer into a detection device. We can trap and subsequently analyse quantities below 1 part per billion.”
Bruno and colleague Tara M Lovestead used dead feeder rats, taking samples of rats buried under 8cm of soil, laid on top of soil and from boxes with no dead rats in them. They took samples at one week intervals for six weeks, and then again at 10 and 20 weeks, finding the level of NRN was at its highest after five weeks, but still detectable after 20.
The device is operable at room temperature – a big plus for future portability – and employs chemicals already in use by law enforcement officials. Bruno is now working on a portable version of the instrument which may be used in the field.
