Indianapolis Metropolitan Police are looking for the person throwing rocks off a bridge at cars passing underneath. A motorist called police about 1 a.m. Monday after hearing what sounded like gunshots near East 30th Street and Emerson Avenue. Officers showed up to find three drivers had bricks and large rocks thrown at their cars. This is at least the third time rocks or bricks have been thrown onto vehicles in this area within the past four months. Police have not made any arrests.