A recent article on PoliceOne.com highlights some lawsuits brought in TX to challenge using K9s to make suspect identifications. The article is here:

http://www.policeone.com/K-9/articles/1851697-Lawsuits-target-Texas-K-9-scent-lineups/

Of course the arttorney's for the plaintiffs make the assertion that there is :junk science" behind the idea of scent identification. This is absolutely not the case, but who expects a lawyer to worry about the truth. Now, it is possible that the scent identification procedures set up in the case in TX may have been flawed in some way, or that the dogs and handlers have not had the appropriate training, but to argue that the concept is faulty is not the case.

I had the pleasure to attend a semiar given by the Dutch Professor Dr. Adee Schoon, of the University of Leiden, Netherlands, present her research, and its application in Dutch Law enforcement. Here is a sample of her writing on the subject. There is no shortage of research and empirical studies to show that dogs can in fact make proper scent identifications, but the procedures used are critical to getting success, and not every K9 and handler are cut out for this kind of work. A lot of training has to go into this and I would venture to say, there are few if any K9s in the US who have had proper scent identification traiing, or that the procedures used to conduct the same are scientifically valid. To read more about it, check out Adee Schoon's research, contained in the book K9 Suspect Discrimination :

http://www.amazon.com/K9-Suspect-Discrimination-Adee-Schoon/dp/1550592335

 Here is a link to an FBI newsletter article about the subject of scent in criminal investigations, it contains an extensive bibliography:

http://www.fbi.gov/hq/lab/fsc/backissu/july2004/research/2004_03_research03.htm

While there are limitations, this is an area of K9 use that will grow in the future, and handlers interested in this subject must get the proper training and use proper best practice procedures, and not rely on old wives tales.