A Massachusetts State Police trooper is on administrative leave after prosecutors accused him of assaulting his wife.Michael Atton, 34, of Wrentham, was arraigned in Wrentham District Court Monday. He pleaded not guilty to a charge of assault and battery on a family or household member.Wrentham police were called Saturday to an apartment complex along Ledgeview Way called The Point Apartments for a woman who had fallen by the pool.The alleged victim, Atton’s wife, had older bruises on her arms