WATERTOWN, MA – APRIL 19: Boston Police mobilize in the parking lot of the Watertown Mall on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school’s campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. According to reports, one suspect has been killed during a car chase and the police are seeking another – believed to be the same person (known as Suspect Two) wanted in connection with the deadly bombing at the Boston Marathon earlier this week. Police have confirmed that the dead assailant is Suspect One from the recently released marathon bombing photographs. Jared Wickerham/Getty Images/AFP