The U.S. Court of Appeals for the Seventh Circuit recently made a ruling on the use of drug sniffing dogs in U.S. vs. Bentley. Trained dogs have very sensitive noses and are able to identify drugs, but the problem in police forces is that dogs are also hard-wired to please humans. So, if the handler has a preconceived idea of who might be concealing drugs, the dog is more likely to act off of those cues.
Studies that back this up show that tests designed to mislead handlers are more effective than those designed to mislead dogs. Another telling contrast is that between trained drug sniffing dogs and trained mine sniffing dogs. Mine sniffing dogs are significantly more accurate, with mines, handlers are unlikely to have an idea of where mines are hidden and there are no incentives for the dogs to make false identifications. Studies in Chicago found that drug sniffing dogs were much more likely to make false positives on Latinos, indicating that they were operating on the bias of their handlers.
Drug sniffing dogs that alert their handlers when no drugs are found essentially circumvent the 4th amendment. Lex, the dog in U.S. vs. Bentley, had a 93 percent alert rate, and was only right about the presence of drugs 60 percent of the time. So, the dog frequently operated as a gateway to probable cause. This behavior was reinforced by his handler – every time Lex alerted (not every time a search resulted in finding drugs) – he was rewarded with a treat.
In the Bentley case, the suspect was transporting a large amount of cocaine. However, even if unlawful search and seizure results in the detection of illegal activity, the concern of those watching this and other cases is that the rights of the citizenry are being abandoned in because the ends are advantageous even though the means are questionable.
Your rights, including during search and seizure, are an important part of any legal proceedings and a seasoned criminal lawyer will make sure that those rights are being protected under the law.