EDGARTOWN — An Oak Bluffs man pleaded not guilty Monday in connection with a crash Saturday night in which a woman was killed in Tisbury. Zachary A. Dupon, 25, was arraigned in Edgartown District Court on Monday on charges of homicide by reckless operation of a motor vehicle, marked lanes violation and speeding. He is being held without bail. Dupon was driving a 2002 Nissan SUV on Saturday night on Beach Road when he moved into the opposite lane to pass two vehicles in front of him. While in the opposite lane, he struck a 2010 Volkswagen Beetle head-on, according to the Massachusetts State Police.