From the Boston Globe:
WATERTOWN — One suspect in Monday’s Boston Marathon bombings has been apprehended, according to an official with knowledge of the investigation. Another appears to remain on the loose in Watertown after a firefight with police. A 20-block perimeter was established as authorities searched for him.
The Middlesex District Attorney’s office said that the suspect taken into custody was pronounced dead at a hospital. The DA’s office did not independently confirm the connection to the marathon bombings.
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 armed carjacking led police on a frenetic chase into Watertown. Hundreds of police officer flooded Cambridge and Watertown.
Update I: AP is reporting that the two bombers are from Chechnya and have been in this country for about a year.
Update II: And the second suspect is in police custody. Good swift work to all involved:
In the waning moments of daylight, police descended Friday on a shrouded boat in a Watertown backyard to capture the suspected terrorist who had eluded their enormous dragnet for a tumultuous day, ending a dark week in Boston that began with the bombing of the world’s most prestigious road race.
The arrest of 19-year-old Dzhokhar Tsarnaev of Cambridge ended an unprecedented daylong siege of Greater Boston, after a frantic night of violence that left one MIT police officer dead, an MBTA Transit Police officer wounded, and an embattled public — rattled again by the touch of terrorism — huddled inside homes.
Tsarnaev’s elder brother and alleged accomplice — 26-year-old Tamerlan Tsarnaev, the second suspect in Monday’s Boston Marathon attack — was pronounced dead early Friday morning at Beth Israel Deaconess Medical Center, after suffering shrapnel and bullet wounds in a gunfight with police.