An off-duty Boston Police officer on Washington Street in Roxbury did a double take today when he observed an individual who looked exactly like the person in a wanted poster hung at the Area B2 police station. The officer followed the suspect on foot and requested back-up as Michael Williams, 26, of Dorchester, was wanted on warrants for Assault & Battery with a Dangerous Weapon and Armed Robbery. When other officers arrived, Williams was arrested without incident.On June 12, 2006, a suspect later identified as Michael Williams walked into the Bank of America on Brookline Avenue, indicated that he had a gun and demanded money. Williams fled in a vehicle that was later located by officers with money and other evidence inside, however, Williams was nowhere to be found. When arrested today, Williams was also in possession of drugs and will be charged with Possession of Class A and Class E drugs as well as Failure to Appear in Court. He will be arraigned in Roxbury District Court tomorrow.