The situation in Boston that Dominic told you about earlier this evening is still developing. Now the Boston Globe says:

One marathon suspect 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.

I'm following the #watertown hashtag on Twitter and listening to the WCVB livestream and the Boston Police, Fire, and Emergency scanner and will update if new information comes in.

UPDATE 11:42 PM: The Boston Globe report seems to be based on a single source, so please bear in mind that this could be another false alarm. Meanwhile, other Boston news outlets are saying that the one Watertown shooter who was taken into custody has died.

UPDATE 11:49 PM: Police on the scanner are referring to the suspect on the loose as the man in the white hat from the Boston Marathon bombing photos that the FBI released today. The actual quote on the scanner was "the party that is outstanding is the party with the white hat that was identified in the photos."

UPDATE 12:02 AM: The name Sunil Tripathi is getting tossed around a lot on Twitter right now, saying it was mentioned on the BPD scanners. In fact, "Sunil Tripathi" is at the top of the US Twitter trending topics right now. This is a name that started showing up on Reddit amateur sleuth threads earlier this afternoon in connection with the bombing. Tripathi is a Brown student who disappeared last month, leaving a cryptic note. Authorities have not released the contents of that note. Here's one story about his disappearance. Here's another. Here's all the information Reddit has on Tripathi. Here's a cache of the Tripathi family's "Help Us Find Sunil Tripathi" Facebook page, which was taken down around eleven o'clock tonight. It's important to note that this is all internet speculation, and Twitter might be seriously CNN-ing this whole story right now. (Also part of Reddit's investigation: In late March, some homemade explosives were found near Hanover, MA.)

UPDATE 12:36 AM: Police on the scanner are asking for buses to evacuate the area, leading some to speculate that there are explosive devices in the area. According to the scanner, they've got the area "locked down" and are waiting for daylight. Citizens are advised to stay in their homes.

UPDATE 1:10 AM: Boston's Police Commissioner has reportedly confirmed that the suspect taken into custody, the Marathon bomber in the black hat, has died.

UPDATE 1:15 AM: Boston PD just tweeted this:

UPDATE 1:33 AM: Someone on the scanner warned police to use extreme caution, because the suspect "might have an explosive on his person."

UPDATE 1:39 AM: MIT has tweeted that "a suspicious package" has been found on Memorial Drive. UPDATE UPDATE: False alarm!

UPDATE 1:56 AM: We're still about an hour away from daylight in Massachusetts. Now NBC is raising doubts about the internet's Tripathi theory:

UPDATE 2:21 AM: Williams has directly refuted the Tripathi rumors, saying that his sources say the bombers "were foreign nationals. They were here legally." He also says they panicked when their photos were released today. If Williams is right, Reddit is going to have to turn in its shiny new police detective's badge. Forty minutes to sunrise.

UPDATE 2:34 AM: At a press conference, a Beth Israel hospital spokesperson said that a patient died there tonight due to multiple gunshot wounds and blast wounds. They wouldn't confirm the patient was the bombing suspect, but I don't think they receive many multiple-gunshot-and-explosion patients in the emergency room on a Thursday night.

UPDATE 2:45 AM: All subway and commuter rail service is suspended in Boston right now. People are told to stay at home, businesses are told to stay closed until further notice. Watertown is on lockdown, 9000 policemen are in the area, and the FBI is moving in.

UPDATE 3:12 AM: This Boston Globe story is just about as good of a "story so far" roundup as I can imagine.

UPDATE 3:30 AM: Now that NBC's Pete Williams has shamed all but the most shameless of Redditors, he's providing more information from his sources, saying that the two suspects are either from Turkey or are Chechen refugees. Just after that, the AP announced that the suspects are "from Russia region near Chechnya." NBC says that they're brothers. But remember that if CNN's epic shit-eating contest from earlier this week taught us anything, it's that sources can be misleading.

UPDATE 3:38 AM I can't keep my eyes open any longer. I have to get some sleep. I encourage you to check out the WHDH livestream, as well as all the resources I linked to above. See you after a couple hours of fitful, unsatisfying sleep, hopefully to news that the second suspect has been captured without incident.

UPDATE 3:49 AM: Okay, okay, one more:

Reddit better get started on those handwritten apology notes now.