How long can police detain me for a traffic stop?

Consider a hypothetical: a police officer stops you for a minor traffic violation. He goes through the usual routine of checking your driver’s license, vehicle registration and proof of insurance, and they all check out. He writes you a warning about the traffic infraction. You think that the encounter is over, and want to get on your way.

But for some reason, the officer does not seem to want to let the matter rest. Next he asks you for permission to walk a drug sniffer dog around your vehicle. You refuse to give permission, and the officer refuses to let you leave. Backup arrives. The officer does the dog pass around your car anyway, and the dog alerts to the presence of an illegal drug. You are arrested for drug possession.

You ask yourself: was it reasonable for the officer to continue the traffic stop once he issued the warning? How long is too long to conduct a routine traffic stop?

Interestingly, earlier this year the U.S. Supreme Court examined this very issue, and its conclusion may make a significant difference in how police perform traffic stops in New York and other states.

The above hypothetical is not just a thought experiment. It really happened to a driver in another state, and his case eventually made its way to the Supreme Court for consideration, and the Court ruled that unless reasonable suspicion exists for the officer to do a drug search, including a dog sniff, he or she cannot extend a traffic stop to search for drugs in your car. The officer can stop you long enough to complete the “mission” of the traffic stop – for example, to issue you a ticket or warning for the original reason for stopping you – but then must let you go without prolonging the stop in the hope that a dog sniff of your vehicle might turn up something.

If you are held longer than you believe is reasonable for a traffic stop, and police use that extra time to do a drug search of your vehicle, you should inform your defense attorney of this – it might make the difference between being convicted of an offense or not.