Law enforcement authorities say one of the suspects in the Boston Marathon bombing was shot and killed by police overnight, meanwhile a massive manhunt is underway for the second suspect in the Boston suburb of Watertown.
The two men led authorities on a police chase after they confronted and killed a Massachusetts Institute of Technology officer and wounded another.
Police say the pair were involved in an armed robbery in Cambridge, Massachusetts before killing that officer.
Police confirm the suspect in the black hat is dead and the suspect in the white hat remains at large.
Boston Police Commissioner Edward Davis says, "We believe this to be a terrorist we believe this a man who has come here to kill people, we need to get him in custody. "
Police are now going yard to yard instructing people to stay inside with their doors locked.
Once again authorities are looking for the man with the white hat in the photos, released Thursday by the FBI.