Which case allowed drug detection dogs to be used during traffic stops?

The case that allowed drug detection dogs to be used during traffic stops is Illinois v. Caballes. In this landmark decision, the Supreme Court ruled that a dog sniff conducted during a lawful traffic stop does not violate the Fourth Amendment, which protects against unreasonable searches and seizures. The Court emphasized that the exposure of luggage to a trained narcotics dog is not a search under the Fourth Amendment, as the dog only alerts to the presence of illegal substances rather than any privacy interest.

The ruling established that as long as the traffic stop itself is legitimate and within a reasonable length of time, law enforcement officers can use canine units to detect drugs, thus allowing them to extend the investigation of a traffic stop if there is probable cause established through the dog's alert. This case solidifies the use of drug-detection dogs as a tool for law enforcement in traffic situations, affirming their role in helping secure public safety against drug-related crimes.