The video, taken in Campbell, Calif., in July, and posted to Facebook by a person who goes by the name of "Feo Mas," shows the officer with his gun pointed at the passenger, who repeatedly asks the officer to lower the weapon.
"Why are you still pointing the gun at me, bro?" the man says. "My hands are right here."
The man's hands are visible, on his lap or in the air, throughout the video.
"Relax," the officer says.
"No, I'm not gonna relax. Get the [expletive] gun off me," the man responds.
The officer said he had become unnerved because he thought he saw the passenger reach for a screwdriver on the floor.
"You asked for registration. You asked for paperwork. That's what we were looking for, bro," the man says.