An Alabama state trooper stopped a car when he saw it veer over the white fault line on an interstate and travel briefly on the shoulder. He asked questions intended to determine whether the driver was too sleepy to drive or intoxicated and then had the driver, Jessie Perkins Jr., sit in the squad car while he prepared a warning ticket.

The officer later testified Perkins seemed extremely nervous, breathed rapidly, was evasive and repeated all of the officer's questions before answering them. His answers to questions regarding his destination were somewhat inconsistent with those given by the car's passenger.

Suspicious, the officer asked Perkins and his passenger numerous questions about whether they had drugs in the car. They denied having drugs several times but, when the officer called for a canine unit to sniff for drugs, Perkins revealed he had narcotics in the car's console.