of that tonight. here's the sequence of events as we understand them right now. at about 10:20 last night, there's a robbery at a 7-eleven in cambridge. after that, an m.i.t. police officer was shot and killed in his head. at that point, the two suspects who are the suspects in the boston marathon bombing, engage in a carjacking and seize a black mercedes suv. the victim in that case, the owner of the vehicle, is kept with them for about a half an hour while they drive through and head towards watertown chased by police. at some point, they let the victim out, and the police chase ensues to watertown at which point there's this fire fight. explosive devices are thrown from the car. one of the suspects is -- an