A Temple University political science major months from graduation was shot and killed off-campus in North Philadelphia Sunday afternoon after he returned from Thanksgiving break, and police are still searching for the gunman. Samuel Sean Collington, 21, of Prospect Park, Pennsylvania, was shot twice in the chest outside his college apartment in the 2200 block of North Park Avenue at 1:32 p.m. His mother, Molly Collington, said her son had just returned to North Philadelphia from his home in Delaware County with clean laundry following the long holiday weekend.