Fuzzy probable cause: police dogs and searches.

• Author: Sullum, Jacob
• Position: Citings

IMAGINE THAT a police officer, after searching someone's car, is asked to explain why he thought he would find contraband there. "A little birdie told me," he replies. Most judges would react with appropriate skepticism to such a claim. But substitute "a big dog" for "a little birdie," and you've got probable cause.

Or so says the U.S. Supreme Court, which in February unanimously ruled that "a court can presume" a search is valid if police say it was based on an alert by a dog trained to detect drugs. The Court thereby encouraged judges to accept self-interested proclamations about a canine's capabilities, reinforcing the common use of dogs to justify searches despite evidence indicating they are much less reliable than commonly believed.

Instead of requiring police to demonstrate that a dog is reliable, the Court's decision in Florida v. Harris puts the burden on the defense to show the dog is not reliable through expert testimony and other evidence that casts doubt on the training and testing methods used by police. But such evidence may be hard to come by. Many police departments simply do not keep track of how often dog alerts lead to unsuccessful searches, and the Court said they are not required to do so...