Four days after he and his older brother, Tamerlan, allegedly bombed the Boston Marathon, killing three and injuring dozens more, 19-year-old Dzhokar Tsarnaev is finally in custody. The days-long manhunt ended as bizarrely and gruesomely as it started: with Dzhokar trapped on a boat in a Watertown, Massachusetts, backyard, covered in blood—possibly his own—and surrounded by police. After a lengthy standoff and a conversation with a negotiator, Dzhokar turned himself over to the authorities.

With both the Tsarnaev brothers out of commission—Tamerlan was killed in a gun battle with cops last night—a nation that considered itself under attack for a week breathes a sigh of relief. But many questions still remain. For instance, who were the three people recently taken into police custody in New Bedford, Massachusetts, in connection with the bombings?

Check back for constant updates throughout the night and weekend. As we follow the developments here, you can read the backstory from Thursday evening and through Friday afternoon here.

Updates:

12:08 AM: CBS News has a surveillance photo of Dzhokar Tsarnaev on the boat before he was taken into custody.

11:57 PM: ABC News has the story of how Watertown, Mass. resident David Hennesberry discovered thatDzhokhar Tsarnaev was hiding in his boat.

"He looked and noticed something was off about his boat, so he got his ladder, and he put his ladder up on the side of the boat and climbed up," [Hennesberry's neighbor] George Pizzuto said. "And then he saw blood on it, and he thought he saw what was a body laying in the boat. So he got out of the boat fast and called police."

11:22 PM: CNN is reporting this is a picture of Dzhokhar Tsarnaev being treated after his arrest. The ATF has confirmed the photo is real.

10:52 PM: The three people questioned by the FBI were released without charge.

And here's another video of the shootout before the arrest:

10:25 PM: President Obama gave a press conference shortly after the arrest. "Our nation is in debt to the people of Boston," the president said. "[They] responded with resolve and determination...Obviously there are many unanswered questions, among them, why did young men who grew up and studied here as part of our communities and our country resort to such violence? How did they plan and carry out these attacks and did they have help? The families killed so senselessly deserve answers. The wounded, some of whom have to learn how to stand, walk, live again, deserve answers."

The president also mentioned the victims of the fertilizer plant explosion in West, Texas, saying, ""I want them to know that they are not forgotten."

Here's the scene at the marathon's finish line:

10:10 PM: The Associated Press has a photo of Dzhokhar Tsarnaev being taken from the scene in the back of an ambulance.

Here's video of the scene as police confronted Tsarnaev earlier in the evening.

9:51 PM: The suspect is in serious condition, according to Boston police.

9:45 PM: Boston residents are celebrating in the streets, cheering police and other emergency personnel.

9:35 PM: CBS is reporting that no Miranda rights will be read to Tsarnaev when he is well enough to be interrogated. The government is invoking the public safety exception.

8:43 PM: An NBC reporter on the scene just said, "It's over." Tsarnaev is in police custody. A wave of applause reportedly broke out amongst the police on the scene.

8:39 PM: Police just took three people into custody in New Bedford, Massachusetts, in relation to the marathon-bombing investigation, according to the Globe.

8:27 PM: NBC Nightly News is reporting that a police negotiator has arrived to try and talk Tsarnaev out.

8:20 PM: Watertown residents tell the Globe that police are saying Tsarnaev is "covered in blood."

8:13 PM: NBC's Pete Williams is reporting that the boat is on fire.

7:48 PM: WCVB is now reporting that it is Dzhokar Tsarnaev in the boat and he is moving.

7:42 PM: The Boston Herald says that the person in the boat is "not moving."

7:35 PM: Boston radio station WBZ 1030 reports that police were able to find the suspect in the boat by using thermal imaging.

7:35 PM: CBS Boston is reporting that Tsarnaeve is alive, on the boat, and surrounded by police. Presumably he is "the body" WCVB was talking about.

7:24 PM: Boston's WCVB reports that the suspect was hiding in this boat behind a home on Franklin Street. It is also reporting that "a body" was discovered on the boat. No word on whose body it is.

7:19 PM: CBS reporter Tim Williams reports that gunfire broke out after FBI agents went to search a boat in a Watertown backyard and discovered blood on it. Tsarnaev is believed to be hiding in the boat.

7:08 PM: The Boston Police Department is asking residents of Watertown's Franklin Street to stay in their homes. This less than an hour after the city's lockdown was lifted.

7:07 PM: The Boston Globe reports that Tsarnaev is "pinned down" in a Watertown neighborhood.

6:59 PM: Jon Humbert, from Seattle's KOMO TV, tweets he just heard "hundreds" of gunshots in Watertown:

6:58 PM: CNN is reporting shots fired in Watertown.

6:54 PM: The FBI admitted today that it interviewed Tamerlan Tsarnaev two years ago at the behest of "a foreign government," who thought he had extremist ties.

6:49 PM: Tactical teams are being withdrawn from Watertown, but state police support will remain, according to state police representatives.

6:40 PM: A Watertown local tweets a view of what the neighborhood looked like for most of today:

6:25 PM: The press conference ends without much new information being shared, but, again, Boston is no longer on lockdown.

6:18 PM: Alben: "My message to the suspect is to give himself up."

6:15 PM: Alben clarifies that the Tsarnaev brothers were not involved with a 7-Eleven robbery last night, as has been widely reported. They were at a 7-Eleven, but the robbery happened at a different store around the same time. He says the brothers' presence was "coincidental."

6:14 PM: Alben says he believes Tsarnaev is still in Massachusetts.

6:10 PM: The Boston lockdown has been lifted, but Governor Deval Patrick says the public "must remain vigilant."

6:05 PM: State Police Colonel Tim Alben says in a press conference, "We do not have an apprehension of our suspect this afternoon, but we will have one."