UPDATE The suspects are brothers: Tamerlan Tsarnaev, 26, and Dzhokhar Tsarnaev, 19. Dzhokhar was born in Kyrgyzstan and remains at large. Tamerlan was born in Russia. Both brothers were legal residents.
Boston police have asked all city residents to "shelter in place" as the manhunt for Dzhokhar continues.
Boston police confirm they are searching for "Suspect 2," the man who was identified as a suspect in the Marathon bombings wearing a white ball cap in photos released by the FBI Thursday.
The other man, Suspect 1, was killed during a firefight with law enforcement early Friday morning following the fatal shooting of an MIT campus police officer around 10 p.m. Thursday and the ensuing manhunt in nearby Watertown, Mass.
Boston Police confirmed at a press conference early Friday morning the man killed was identified as the same as "Suspect 1" in the Boston Marathon bombings. "Suspect 2," the man shown wearing a white hat, remained at large.
One suspect dead. One at large. Armed and dangerous. White hat suspect at large.— Edward Davis (@EdDavis3) April 19, 2013
Thursday night's events began on MIT's campus in Cambridge, when the two suspects robbed a 7-Eleven and killed the responding MIT campus police officer.
Attention shifted to nearby Watertown after police received reports of a carjacking of a Mercedes SUV. Police chased the suspects to Watertown, where the fugitives lost control of the Mercedes and crashed, escaping the car by tossing a bomb out the car window.
Local police, ATF officials, FBI and National Guard soldiers all converged on Watertown, setting up a perimeter around a several-block area where they exchanged gunfire with suspects.
State Police confirmed around 3 a.m. Friday that one suspect was taken into custody and another suspect was at large, telling media on the scene there was a "strong link" from the suspects to the murder of the MIT officer and the standoff in Watertown.
The captured suspect was wounded in the gunfight after he got out of the car with explosives strapped to his chest. He was later pronounced dead.
The other suspect drove on an later abandoned the car.
State police spox now says there is one person accounted for and one at large. He says the person they have is headed to the hospital.— Jess Bidgood (@jessbidgood) April 19, 2013
Police said they were investigating a connection to the Boston Marathon bombings.
A pressure cooker, similar to the ones used as explosives in the marathon bombings, was located on the scene in Watertown.
Chatter on police scanners identified the suspects in the Watertown standoff as Tripathi and Mike Mulugeta, but that identification is unconfirmed.
Later information appeared to refute the speculation that Tripathi is one of the suspects, but neither has been publicly identified. According to NBC News, the two men have "international ties," possibly with military training, who may have been in the United States for about a year.
UPDATE: MBTA officer being treated for gunshot wound in hunt for bombing suspects— The Boston Globe (@BostonGlobe) April 19, 2013
View Shootings 4/19 MIT && Carjacking, possibly unrelated in a larger map Suspect 1, left, and Suspect 2, possibly missing Brown University student Sunil Tripathi.