This is a breaking active story, but the Boston Globe is reporting they have a suspect in custody.
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One suspect in Monday’s Boston Marathon bombings has been captured, according to an official with knowledge of the investigation. Another remains on the loose in Watertown after a firefight with police. Authorities have established a 20-block perimeter as they search for him.

A scene of chaos descended on Cambridge and Watertown late Thursday night and early Friday morning, as police confirmed an MIT police officer was shot and killed, and an apparent carjacking led police on a wild chase into Watertown.

Witnesses in Watertown said they heard explosions. Police officers were screaming about improvised explosive devices.

Authorities would not comment on whether the events were connected to Monday’s Boston Marathon bombings. At least one of the suspects in Watertown appeared to be a man in his 20s.

FBI agents were on the scene in Watertown.

Continue reading on www.bostonglobe.com