Livecast: Door-to-door: U.S. police hunt for 'suspect number 2'
Active Manhunt in Boston / Watertown. Police is looking from door to door
- Police: One suspect in Boston Marathon bombings killed, another on the loose in Boston area
- MIT police officer fatally shot Thursday night
- Sometime after shooting, police say, a suspect in the Boston bombings was killed in a shootout with authorities.
- Police say they're looking for "Suspect No. 2" in Monday's bombing in the Boston suburb of Watertown.
- see CNN affiliates WBZ; WCVB; WHDH
After three days of poring over photos and video, investigators appealed to the public to help them identify two men now considered suspects in the Boston Marathon bombings.
The men were photographed walking down Boylston Street, one behind the other, near the finish line of Monday's race.
Suspect 1 was seen wearing a light-colored, collarless shirt underneath a dark-colored jacket and wearing a dark baseball cap.
The man identified as Suspect 2 was seen setting down a backpack at the site of the second explosion "within minutes" of the blasts that killed three people and wounded nearly 180, said Special Agent Rick DesLauriers, the head of the FBI's Boston office. He was wearing a light-colored hooded sweatshirt, a black jacket and a white baseball cap turned backward.