Drug-sniffing dogs can give police probable cause to root through cars, but the dogs have been wrong more often than they have been right about whether vehicles contain drugs or paraphernalia, reports the Chicago Tribune. The dogs are trained to dig or sit when they smell drugs, which triggers automobile searches. A Tribune analysis of three years of data for suburban Illinois departments found that only 44 percent of those alerts from dogs led to the discovery of drugs or paraphernalia. For Hispanic drivers, the success rate was 27 percent.
Dog-handling officers and trainers argue the canine teams’ accuracy shouldn’t be measured in the number of alerts that turn up drugs. They said the scent of drugs or paraphernalia can linger in a car after drugs are used or sold, and the dogs’ noses are so sensitive they can pick up residue from drugs that can no longer be found in a car. Even advocates for the use of drug-sniffing dogs agree that many dog-and-officer teams are poorly trained and prone to false alerts that lead to unjustified searches. Leading a dog around a car too many times or spending too long examining a vehicle can cause a dog to give a signal for drugs where there are none, experts said.