OUR COVERAGE CONTINUES: To get the latest on the manhunt, including the reported identities of the suspect, click here for our latest updates.

3:30 a.m.: More details of the night's chronology have come into focus. Simply speaking, a series of violent events culminated in Watertown, Massachusetts late Thursday night after two unidentified suspects engaged with police from a Mercedes SUV. As many as 100 police officers faced off against the two suspects, who were armed with explosives and firearms. While fleeing, the suspects in the SUV lost control and crashed the vehicle and made their way out of the situation by tossing a bomb towards authorities. The bomb exploded, and the suspects continued to flee, later dropping backpacks that police fear may contain explosives. After police ultimately got one suspect in custody, the bomb squad moved in on the backpacks with a robot. The other suspect is still free.

On top of it all, a transit worker was shot just after 3:30 a.m. in an incident "related to the rest of the mayhem this evening," to borrow the words of The Boston Globe's Jennifer Peter.

Update 3:09 a.m.: CNN showed footage of a naked man being loaded into a police car:

Update 3:00 a.m.: There was a mention on police scanners recently that the suspects in custody are Mike Mulugeta and Sunil Tripathi. The latter is a missing Brown student who was identified on Reddit as a possible suspect earlier this week. However, the chatter is not confirmed.

Update 2:55 a.m.: CNN is reporting that a second suspect is in custody. Gabe Ramirez described the suspect as having "dark hair, short cropped dark hair." Meanwhile, video from the earlier shootout has been posted:

Video via Starkness

Update 2:47 a.m.: Police scanners indicated that a white suspect in a grey hoodie was on the loose and he "could have IED explosive on him so please use extreme caution." As heard on the scanner: "One suspect has been shot, according to one law enforcement source, and FBI is responding to multiple crime scenes.... We're going to see increased federal presence... Undetermined at this time"

Update 2:25 a.m.: The Boston Globe reports that one of the marathon bombing suspects is in custody, after a daring chase through Cambridge. State police later said that they couldn't confirm the link and the total number of suspects was unknown. At least one suspect remains at large. Meanwhile new photos of the suspects have been released.

 

Original Post: MIT issued an emergency alert at 10:48 on Thursday night reporting shots fired on the university campus. MIT's school newspaper, The Tech, reports, "Shots fired near 32 Vassar St (Stata Center), police officer down. Please stay inside." That report is backed up by CBS News's Bonney Kapp who reports hearing "officer down" on the police scanner just before the MIT alert went out. The Tech followed up a few minutes later, reporting that the injured officer was a member of the MIT campus police and was taken to Mass. General Hospital. According to the Massachusetts State Police, the officer died from his wounds just before midnight.

Not long after midnight, there were reports of a car jacking at a gas station on Memorial Drive. The suspects took a Mercedes SUV. Minutes later there were shots fired in Watertown. Then an officer said "they have explosives and grenades." There were also reports of a Camaro and a Honda Accord being involved. After the exchange of fire, police scanners reported an officer down. The chase continued and there were reports of automatic gunfire and explosives being thrown out of a car. Minutes later police took one suspect into custody, and the other fled. Police then set up a perimeter and as many as 50 officers searched for the suspect in Watertown near Mount Auburn Street and Lloyd Road. Officers were told to power down their cell phones, and a stand off ensued.

As police searched for the missing suspect, networks struggled to connect the shooting at MIT, the car jacking in Cambridge and the shootout in Watertown. Underneath all of this is the ultimate connection to Monday's bombings at the Boston Marathon. The presence of the FBI supported some these hypotheses, but very little is actually known about the incidents and possible connections. The FBI was on the scene in Watertown. "This is still extremely dangerous," said the bureau. 

Stay tuned for live updates from ABC Boston below, as well NBC Boston here, the Boston police scanner, plus several local reporters on the scene. 

 

Local news reported that this was the gunman:

Image via Twitter / Akitz


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The suspect remains on the loose and considered armed and extremely dangerous. Meanwhile, the university's ordered all students and staff to remain indoors.  

Image via Twitter / Matt Tomlin

The following photo of the scene of the shooting is graphic:

Image via Twitter / The Tech

Building 32 is circled in red: