“Are Drug Dogs Unreliable? Yes!” by John F Hays, a Seattle Private Investigator.
The Washington Post just published an article that says that the science on the subject indicates “that drug dogs have disturbingly high rates of ‘false alerts’, sometimes with error rates well above 50 percent”. The article indicates that drug dogs can be deliberately or inadvertently influenced by their handlers. If this is true, the validity of evidence developed from the use of these dogs is questionable, at best. This should be the subject of a lot of discussion in the criminal justice system, especially in the criminal defense sector.
Check these links and others (in the article) collected by Radley Balco, the author of the above noted Washington Post article.