Saco police charged a Biddeford man with trafficking in heroin after a tip led police to pull over his car.

Saco police learned that a man driving a beige 2000 Buick Lesabre was likely headed into town Thursday at 5:22 p.m. and that he had heroin with him.

Police pulled over Steven Bergeron, 52, after he was seen allegedly speeding and crossing over the center line on Tasker Street.

Ranger, a police dog, detected contraband in Bergeron’s jacket pocket, police said, and an officer found heroin as well as packaging material. A search of the car turned up more heroin, police said.

In all, police seized 4.6 grams of heroin.

Bergeron is charged with a Class B felony and was taken to York County Jail in Alfred. He is being held on $500 bail.