Police K-9 or cadaver K-9: when to use both
Recently I was posed with a question with regard to an area search. Could my partner do a search of an area where a vehicle had flipped over several times, and the driver or any passengers could not be located? Add to this that there was an approximate 12-hours lapse from when the accident had happened. So at what point in this situation is your police K-9 no longer effective? When is it time to a cadaver K-9?
We first have to understand what a police K-9 and a cadaver K-9 are scenting when they are working. Both are searching for the scent of a person. They are different in the type of scents they are searching for. A police K-9 searches for the living scent of a person. For example, as they walk through a field, his scent is embedded into the grass, dirt and brush. The scent is a combination of body scent, individual chemical makeup of the person, soap, perfume, deodorant, hairspray, smoke odor. They also scent the persons sweat and adrenaline that they omit.
They do this by tracking and wind scenting. A cadaver K-9 searches for the decomposed scent of a person. When a person dies and the blood stops flowing, the body begins decomposing. As the body goes through decomposition it begins to omit gases. These gases along with skin “rafts” and blood is what the K-9 is trained to scent and find.
Knowing how both K-9 work tells us a little of when a police K-9 would no longer be effective. From the research that I’ve done, the release of these gases occurs over a period from 12 hours to several days. A lot depends upon the temperature and humidity conditions of the area of the search. So the answer to the question is there is no definitive answer.
Where a police K-9 can still search for a deceased person, because of the scents that I described above are still being emitted. It must be understood that once the gases begin to be released they will almost always mask the scents the police K-9 are attempting to locate. For a cadaver K-9 to locate the person gases must start to be emitted, unless there is a belief that the person is bleeding, for which a cadaver dog must be trained in (some are not!).
I would use my K-9 to search for someone whether they are alive or dead a full day from the time of the incident. I feel that anything after this time a cadaver K-9 would be more effective. Once again, taking into consideration the temperature and humidity for the area I might extend or shorten this time. A lot depends if you have access to a trained cadaver K-9 (some places do not). Remember that if you do not have access to a cadaver K-9, you are not losing anything but time for trying. I hope this has helped should you ever be faced with a situation or incident like the one above.