If a police officer stops you for a minor traffic violation, how long should the officer be permitted to detain you? Suppose the officer issues you a ticket or a warning for the minor traffic violation and then says he wants you to wait while he has a drug dog sniff your car? What do you say? If you say no, can the officer do it anyway?
Suppose an officer detains a person for violating a traffic law and it turns out the person really didn’t violate the law: the officer was simply mistaken about what the law says. Until recently, one would expect that any evidence obtained after the mistaken detention would be thrown out. In a recent case, however, the U.S. Supreme Court concluded any evidence obtained after the officer mistakenly detained the person is not excluded from trial, so long as the officer’s mistaken belief about the law was reasonable.