On the trail to solve a missing child's disappearance, Portugal had brought in their cadaver dogs to try and snuff out and prove their theory on the child's loss. Cadaver dogs are said to be able to pick up a scent of a dead body from a place it had been. Results on the outcome of the cadaver dogs' at the missing child case is yet to be established, disputes as to whether the dead bodies smelled by the dogs are from another plausible source.  Just how effective are these dogs?

Cadaver Dogs are a result of research done with the help of the RCMP Civilian Search Dog Association by Dr. Deb Komar. Training techniques were first published with an assurance of near 100% accuracy in the Journal of Forensic Anthropology.

Known as Human Remains Detection unit or Cadaver Dogs have been trained to detect, trace and track the odor of decomposing bodies. Dogs have been used as narcotics, bomb and contraband tracers, smelling for dead bodies is not far behind. These dogs are keen and trained to be able to smell a cadaver or traces of a cadaver in a given place accurately.

Choosing a cadaver dog is crucial since the dog must have a good demeanor, innately obedient and is not put-off by the smell of a dead body. Basically a cadaver dog is trained in several search techniques first before it is trained specially for cadaver searches.

Both dog and handler are taught to work in coordination, their first course as a team would be of Person Search, basic in all training for all SAR operations. After about a year all dogs have Large Area Search training for searching in large area grids. After dogs exhibit the tenacity for these searches, they are trained in Small Article searches. The search is for assistance in evidence gathering, with training mostly in open field. To train dogs for any search places, Ditch Search which combine both Small Article and HRD. There is also training in Alleyway Searches that concentrate on asphalt with a mix of smells that may throw-off a scent. Tracking and trailing is a basic training that the dogs participate in, this is when dogs have to search large areas in any terrain. The SAR dogs and handlers are also taught techniques in searching in the water as a team. All handlers and dogs are trained to use the wind and search with the odds in their favor. Special training is given to dogs that have passed the basic SAR training and have no reversion towards dead bodies to make the HRD unit.

Accuracy on detecting dead bodies by cadaver dogs has been tested in rubbles of avalanches, earthquake debris and downed infrastructure. These dogs were noted to have been used in searching for bodies of those buried during the 9/11 terrorist attacks. The accuracy of the Cadaver Dogs has yet to be tested when it comes to trace smells from moved dead bodies.