Photo Gallery: Boston manhunt: Friday, April 19, 2013 17/60

A sharpshooter trains his sight on a building as neighborhood residents stand on the street while searching for a suspect in the Boston Marathon bombings in Watertown, Mass., Friday, April 19, 2013.Two suspects in the Boston Marathon bombing killed an MIT police officer, injured a transit officer in a firefight and threw explosive devices at police during their getaway attempt in a long night of violence that left one of them dead and another still at large Friday, authorities said as the manhunt intensified for a young man described as a dangerous terrorist. (AP Photo/Charles Krupa) ORG XMIT: MACK127