Updated: Boston bomb hunt: man shot dead

One of two suspects in the shooting of a campus police officer is dead and a massive manhunt is under way for another, who is tied to the Boston Marathon bombing, police said today. Shortly after the Massachusetts Institute of Technology officer was shot late last night, police got a report of a carjacking in Cambridge, just outside Boston. Police said of the at-large suspect, "We believe this to be a terrorist." Residents of the Boston suburb of Watertown have been advised to keep their doors locked and not let anyone in. The Middlesex district attorney said the two men are suspected of killing the MIT police officer, then stealing a car at gunpoint and later releasing its driver unharmed. Hours earlier, police had released photos of the bombing suspects and asked for public help finding them. Authorities said the suspects threw explosives from the car as police followed it into Watertown. The suspects and police exchanged gunfire and one of the suspects was critically injured and later died. Police say the suspect on loose is a "terrorist" who "came here to kill people". The MIT officer had been responding to report of a disturbance when he was shot multiple times, according to...