Local police are urging residents to lock car doors and remove valuables from vehicles, even if parked in a driveway, after a series of car break-ins this month. Officers were able to arrest one suspect who allegedly used a stolen credit card, Police Chief Michael D’Entremont said, but the break-ins were still happening. Last Sunday, 11 cars were broken into along the Boston border. “People just walk down the street pulling handles,” D’Entremont said. “When a car is open, they enter it and take whatever they can sell.” He said the crimes usually happen in the late night or early morning hours. Residents are encouraged to report unusual or suspicious activity to the police.