FAIRFIELD — A motor vehicle stop for misusing a license plate turned into drug arrest, thanks to police dog Jagger.

The incident unfolded around 1:30 p.m. Thursday on Commerce Drive, near Coolidge Street. During the traffic stop, Jagger conducted an “air scent” on the car’s exterior and alerted to the presence of a narcotic odor on the driver’s door seam.

Searching the interior, Jagger alterted again to the presence of drugs. Officers found and seized an undisclosed amount of marijuana and ecstasy from the driver, and a small amount of pot from the passenger.

Freddie M. Jackson, 31, the driver, was charged with possession of narcotics, possession of marijuana, and several motor vehicle charges. Jackson lives on Washington Avenue, Bridgeport,

Passenger Vincent Ambrose, 30, of Iranistan Avenue, Bridgeport, was issued a citation for possession of marijuana.

Both were released at the scene on a promise to appear in state Superior Court in Bridgeport.