More on Cadaver Dogs:
From X,
http://www.independent.co.uk/news/s...uth-behind-the-crimescene-canines-835047.html
One of the questions surrounding human cadaver dogs is how soon after death they can recognise a corpse, and how long a "fresh" corpse must remain in one place for a dog to detect that it has been there. In a study published last year, the forensic pathologist Lars Oesterhelweg, then at the University of Bern in Switzerland, and colleagues tested the ability of three Hamburg State Police cadaver dogs to pick out of a line-up of six new carpet squares the one that had been exposed for no more than 10 minutes to a recently deceased person.
Several squares had been placed beneath a clothed corpse within three hours of death, when some organs and many cells of the human body are still functioning. Over the next month, the dogs did hundreds of trials in which they signalled the contaminated square with 98 per cent accuracy, falling to 94 per cent when the square had been in contact with the corpse for only two minutes. The research concluded that cadaver dogs were an "outstanding tool" for crime-scene investigation.
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The carpet square that was kept under the corpse for 10 minutes was reliably "sniffed out" by the dogs 65 days after that 10 minute exposure. (These carpet squares never actually came into contact with the corpse, as it was fully clothed.)
Reference:
Cadaver dogs--a study on detection of contaminated carpet squares.
http://www.sciencedirect.com/scienc...serid=10&md5=f92324578ace13b8c3c1f265b88b6158
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SUMMARY:
A carpet square left in contact with the clothing of a recent corpse (less than 3 hours old) for as little as 10 minutes can be reliably detected by cadaver dogs at least 65 days afterwards.
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Also, there is lots of research about (live) human odor scents. They remain perceptible to dogs for many months. One example:
G.A.A. Schoon (Netherlands National Police Agency and Leiden University) investigated how the age of odor trace evidence affects the performance of Dutch and German scent identification dogs. Although the dogs performed faultlessly in matching odors collected on the same day, their performance level dropped when presented with scent evidence stored for two weeks. After this initial drop, aging did not significantly diminish the dogs performance even with scent evidence aged up to six months.