Metro Nashville Police say they have stepped up security at a downtown bus terminal after 4 teens were hit by gunfire Monday afternoon. Police say they are seeking a 16-year-old youth suspect as the shooter. He will be charged with attempted murder and aggravated assault. The bus transfer station is located in the heart of the state government district. Some 15,000 use the location daily, including some 4,500 Metro School students. Police and school officers day at least 8 officers or security guards are on site at any given time and the station is covered by 44 surveillance cameras.