Found the following interesting regarding the skills of these dogs, also when one dog lost the scent a different dog was used to pick up from there and follow it to the destination.
If the investigation had been unsuccessful the trail followed by the dogs would have allowed evidence to be gathered which would have led to the conviction. Quite extraordinary work on their part.
Don't know why the guy only got 16months though, I would have thrown the key away.
I have always thought the GNR dogs had something regarding Madeleine ... we just do not have the ability to work out what it was.
Case ExampleOn May 13, 2002, a U.S. mail carrier in Philadelphia discovered a package in a mailbox that appeared to be an improvised explosive device. The Philadelphia Police Bomb Squad responded and rendered the device safe.
In a mailbox 1.5 miles away, a similar package was found the following day and rendered safe.
Two days later, human scent was collected with the STU-100 from the remains of these two packages. Starting the dog at one of the mailboxes, a positive indication for scent was given, and the dog began to trail.
After two days of car and pedestrian traffic, the bloodhound was able to follow the trail into a neighborhood where the trail ended. A second dog was started in the neighborhood and identified a house occupied by Preston Lit. The criminal investigation, conducted separately from the human-scent work, brought the police
to the same location (Meserve and King 2002). Lit pleaded guilty and received a 16-month sentence in federal prison.
http://landofpuregold.com/the-pdfs/humanscent-crime.pdfI can recommend reading all of the article above, I found it very interesting regarding the training of the different types of dogs and also the fact that they are capable of tracking the main source even if contaminated by other scents.