FAIRFIELD — A couple, suspected in a series of local thefts, was arrested Thursday afternoon on drug charges.

Police had put out an alert to officers for a tan, Saturn station wagon linked to a series of thefts over the last several weeks. A patrol officer spotted the Saturn parked on the Post Road, near Grasmere Avenue, around 1 p.m. The car’s tailgate was open and the officer saw large boxes and construction tools in the car.

Upon checking the registration, the officer found it had expired and stopped the car. Noticing what appeared to be needle marks on Shaun Costello’s arms, the officer asked if there was anything illegal in the car.

According to the report, Costello, 34, told the officer he might find some used needles in the car because he and his passenger, Amy Kiernan, 38, were struggling with addiction. He gave permission for police to search the car, and the search turned up nine wax folds of heroin, a 5-inch double edged knife, and a pot pipe.

Police allege that Costello admitted to he and Kiernan committing thefts in Fairfield while driving the Saturn.

Costello, who lives on Linen Street in Bridgeport, was charged with possession of narcotics, weapons in a motor vehicle, misuse of plates, operating an unregistered vehicle and having no insurance. He was released after posting a $1,000 bond.

Kiernan, of Burr Street, Stamford, was charged with possession of narcotics and released on a promise to appear in court. Both were given an Oct. 6 court date in state Superior Court in Bridgeport.

Police are continuing to investigate the couple’s involvement in the thefts, and they may face additional charges.

greilly@ctpost.com; @GreillyPost