Editor's Note: The headline of this story was corrected to reflect that the man arrested lives in Worcester. NATICK — Police have arrested a Worcester man who is accused of robbing the Aldi grocery store on Speen Street Wednesday. Police charged William B. Wilson, 56, of 102 Elm St., Worcester, with armed robbery while masked and larceny of more than $250. He is expected to be arraigned Thursday in Natick District Court. The case remains under investigation and more charges could be added, police said. An unidentified man went into the 321 Speen St. store, brandishing a handgun at 12:23 p.m., police spokeswoman Lt. Cara Rossi said. It is not known if it was a real gun or a replica.