Authorities have arrested four people in the shooting deaths of two Mississippi police officers over the weekend, but the sheriff of Milwaukee County — more than 900 miles away, in Wisconsin — says there’s a fifth culprit on the loose. Suspect description: African American, slender build, salt-and pepper-hair, last seen wearing a blue power tie and sounding professorial. His alias: President Barack Obama. Less than 24 hours after Officers Benjamin J. Deen, 34, and Liquori Tate, 24, of the Hattiesburg Police Department were gunned down during a traffic stop, Milwakuee County Sheriff David A. Clarke linked the deaths to events...