This decision stems from the case of Roy Caballes, who was pulled over for speeding and subsequently arrested for marijuana trafficking after a drug dog was brought to the scene and alerted on his vehicle. The Illinois Supreme Court reversed his conviction, finding that a drug sniff was unreasonable without evidence of a crime other than speeding.
But in a 6-2 ruling, the Court held that the Fourth Amendment is not implicated when police use a dog sniff during the course of a legal traffic stop. Justice Stevens wrote the Opinion of the Court, finding that since dog sniffs only identify the presence of illegal items — in which citizens have no legitimate privacy interest — the Fourth Amendment does not apply to their use.
The Caballes ruling authorizes police to walk a drug dog around the vehicle during any legitimate traffic stop. If the dog signals that it smells drugs, police then have probable cause to conduct a search.
However, the ruling does not allow police to detain you indefinitely until dogs arrive. The legitimacy of the traffic stop still depends on its duration. Basically, if police can’t bring a dog to the scene in the time it takes to run your tags and write a ticket, the use of the dog becomes constitutionally suspect. So if you’re pulled over and police threaten to call in the dogs, you are not required to consent to searches.
Usually, the officer won’t have a police dog on hand and he needs reasonable suspicion to detain you while waiting for the drug dog. Before the dog arrives, you have the right to determine if you can leave by asking “Officer, am I free to go?” If the officer refuses and detains you until the dogs come, you have the right to remain silent and refuse to consent to any searches.
If a dog arrives, you have the right to refuse to consent to a dog sniff, even if the officer claims you have to. Be aware that unlocking your car at the officer’s request or handing the officer your keys is the same as consenting to a search. You always have the right to refuse by stating “Officer, I don’t consent to any searches.” (Repeat, if necessary.)
If a judge determines that the officer had no justification to detain you until the dog arrived, any evidence discovered by the dog may be thrown out in court.
Caballes does not constitute a significant change in the constitutionality of dog sniffs. This case essentially clarifies previous rulings in which the Court was reluctant to apply the Fourth Amendment to the use of drug dogs.
The ruling also does not apply to the use of police dogs in situations other than legitimate traffic stops. For example, suspicionless dog sniffs in parking lots or on sidewalks are not authorized by Caballes, and the Court has found random drug checkpoints unconstitutional. Nonetheless, the Court’s “no privacy interest in contraband” doctrine is a nasty one, but it might open up possibilities for future legal challenges.
The Supreme Court recently agreed to hear a case that casts doubt on the effectiveness of drug dogs to generate probable cause for a vehicle search. In Florida v. Harris, the Florida Supreme Court ruled that a drug dog’s reliability record must also be considered to determine probable cause.
The case will provide long-due scrutiny to the legal assumption that dogs are reliable contraband indicators. In their dissenting opinion of Caballes, Justices Souter and Ginsburg pointed to studies showing that drug dogs frequently return false positives (12.5-60% of the time, according to one study). A recent Chicago Tribune field study revealed that drug dogs are more often wrong than they are right when alerting for drugs in vehicles. (Worse, police often train their dogs to falsely “alert” on suspected vehicles.)
A high court ruling in favor of Harris would effectively overturn Caballes, because a dog “alert” would no longer be enough to justify a vehicle search.
17 states and the District of Columbia have legalized the use of medical marijuana for citizens with a doctor’s recommendation. As such, the Caballes “contraband” distinction fails in states such as California or Colorado where hundreds of thousands of people are legally authorized to possess and use it.
After all, if police dogs are regularly alerting on substances that are no longer illegal, that flips the ”no privacy interest in contraband” doctrine on its head. For example, a vehicle search resulting from a drug dog alerting for marijuana in Mendocino or Boulder is unconstitutional under Caballes. The odor of marijuana can no longer be probable cause, because prior to the search it’s impossible for an officer (or a drug dog) to know whether or not the detected marijuana is contraband or not.
While this defense might not work in federal courts — which have yet to recognize the legal standing of medical marijuana — it could be used to challenge dog searches in states that have legalized medical marijuana.