Tuesday, August 4, 2009

A Friend dropped this item in my email box today. Dog Scent Evidence is beginning to smell like the way horses count and do math....




Jeff Blackburn, head of the Innocence Project of Texas, has labeled the dog-scent evidence as "junk, not even junk science." He adds, "We are working on a very intense, independent investigation of Pikett's activities."

Pikett, who through his lawyer has declined public comment, is being sued for civil-rights violations in federal court by Miller and Buchanek. Blackburn says the innocence team is combing Texas public records to assess Pikett's impact on other cases.

In the meantime, the Innocence Project of Texas study is being supported by canine-law-enforcement experts who, while not going so far as to call dog-scent evidence junk, fear that misapplication of the undisputed canine talent for recognizing smells will discredit good cases along with the bad.


The notion of a crime-busting dog can be appealing, not to mention a break for jurors from mind-numbing expert-forensic-witness testimony. But experts caution that it is not the dog who testifies but rather the handler. "The animal knows what he is smelling, and everyone else has theories of what he's smelling," says Russ Hess, executive director of the U.S. Police Canine Association.

For hundreds of years, humans have relied on the ability of dogs to distinguish scents to track prey, whether in the hunt for food or the search for a prison escapee. Bloodhounds are the recognized experts in supersensitivity to odors (some states allow scent evidence only from bloodhounds to be admitted). But even the best-trained scent dog — and Hess says the dogs require constant training — can make mistakes. "They are fallible, just like a person," says Charles Mesloh, a former canine officer and criminologist at Florida Gulf Coast University.

Dogs, he adds, respond to handlers, perhaps for reward or praise, or simply because of emotional connections, wanting to please their human partner. "Dogs aren't stupid — they cheat," Mesloh says. "What goes down the leash, comes up the leash." In the Netherlands, where tough evidence protocols are in place, a suspect scent is taken to a lab, where the dog's reactions are tested without a handler present.

Dogs have proved their value to both the military and law enforcement, Hess says, detecting explosives, working with narcotics officers and locating missing persons and bodies.

But the alleged misuse of dog-scent evidence could cast a shadow over its value to law enforcement. In the 1980s, polygraph tests came into fashion and were hailed as an important forensic tool, but their misuse and overuse prompted a negative public reaction; Mesloh fears the same could befall the use of scent evidence. "The hammer fell on polygraphy, and it never really recovered," Mesloh says. "Now, [for dog scent], the blood is in the water."

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