Seattle Police say the man, who has not been named, was pulled over on December 1 for driving without his lights on - before things took an unexpected turn.
After Seattle Police Officer Nic Abts-Olsen walked back to his patrol car to check the man's driving record, he returned to the Toyota, prepared to let the man off with just a citation. But once there, he saw the man "portioning out a scoop of cocaine from a small glass vial," according to the SPD Blotter.
Officer Abts-Olsen knocked on the window and looked at the man in shock.
"What's that in your left hand?" he asks him in the video. "Are you kidding?"
The man denied it was cocaine and said he only had "vitamins" in the car. Eventually, he admitted the substance was cocaine, police said.
After taking the man out of the car and cuffing him, the incredulous officer asks: "What would possess you to do that on a traffic stop with a police officer right behind you? I just don't understand!"
The man was arrested and booked into the King County Jail for narcotics possession.
Police released the footage to remind motorists: "Please abstain from using cocaine, especially during a traffic stop."