Authorities weren't keeping tabs on Tamerlan Tsarnaev despite his name being on counterterrorism database.
Tamerlan Tsarnaev's name was on the United States Government's highly classified central database of people it views as potential terrorists.
But the list is so vast that this did not mean authorities kept close tabs on him, sources close to the bombing investigation told Reuters.
Tamerlan, 26, was killed in a police shootout, while his brother Dzhokhar, 19, was captured after the Boston Marathon bombings.
Prosecutors contend that the brothers planted the bombs that killed three people and wounded more than 200.
The sources told Reuters that Tamerlan's details were entered into Tide, a database maintained by the National Counterterrorism Centre, because the FBI spoke to him in 2011 while investigating a Russian tip-off that he had become a follower of radical Islamists.
The FBI found nothing to suggest he was an active threat, but still placed his name on the "Terrorist Identities Datamart Environment" list. The database holds more than half a million names and is only a repository of information on people who US authorities see as known, suspected or potential terrorists from around the world.
The Boston Globe quoted Republican Senator Richard Burr as saying that the Russian authorities alerted the FBI "multiple" times over their concerns about Tamerlan, including a second time nearly a year after he was first interviewed by the FBI in Boston.
Republican Senator Susan Collins said there were problems in sharing information before the Boston bombings.
Speaking after the FBI gave a closed-door briefing to the Senate Intelligence Committee she said: "This is troubling to me that this many years after the attacks on our country in 2001 that we still seem to have stovepipes that prevent information from being shared effectively." She did not elaborate.
Tamerlan was not put on the "no-fly" list that would have banned him from boarding a plane in the United States. Neither was he named on the Selectee List, which would have required him to be given extra security screening at airports. Another list, the Terrorist Screening Database, is a declassified version of Tide with fewer details about suspects. One source said he was on this list, too.
Dzhokhar has told investigators in written notes that the brothers were motivated by the wars in Iraq and Afghanistan and a desire to "defend" Islam. Handcuffed to his hospital bed, and still unable to speak after his throat was injured, Dzhokhar's condition was upgraded from "serious" to "fair".
Interrogators are speaking to the teenager every few hours at Beth Israel Deaconess Hospital.
- Telegraph Group Ltd
Owner doesn't want free boat
David Henneberry, the Watertown man who found Dzhokhar Tsarnaev hiding in a boat in his backyard, has told TV station WCVB that he did not see blood on the outside of the boat the first time he looked at it after the curfew was lifted.
But something was nagging at him and he put a ladder up to the side of the boat to take a closer look.
"I got three steps up the ladder and rolled the shrink wrap. I didn't expect to see anything, but I saw blood on the floor of the boat. A good amount of blood ... And I looked back and forth a couple of times and my eyes went to the engine block and there was a body." Henneberry said he does not remember climbing down and rushing to call emergency services. "I didn't waste any time. I didn't ask him if he wanted a cup of coffee. I was off that ladder. That is all I remember," he said.
Henneberry is aware of a growing social media movement to buy him a boat to replace the Slip Away II, but he told WCVB that he does not want it. "It makes me feel wonderful that people are thinking like that, but it is my boat. People lost lives and lost limbs. I'd rather that [the money] go to the One Fund Boston."