Tamerlan Tsarnaev, 26, was killed in a police shootout the same day his younger brother who is the other suspect was captured later that day.
According to investigators, the brothers, who are ethnic Chechens, planted two bombs that exploded near the finish line of the marathon on April 15, which took lives of three people and wounding more than 200.
The sources revealed that Tamerlan Tsarnaev’s details were in TIDE, a database maintained by the National Counterterrorism Center, as the FBI spoke to him in 2011 while investigating a Russian tip-off that he had become a follower of radical Islamists.
The Federal Bureau of Investigation found nothing to suggest he was an active threat, but all the same placed his name on the “Terrorist Identities Datamart Environment” list. However, the authories have revealed no details regarding the elder Tsarnaev.
But the database, which contains more than half a million names, includes information on people who U.S. authorities see as known, suspected or potential terrorists from over the world.
U.S. investigators explain that because of the great number of names listed in their database they simply have no time to routinely monitor everyone registered there.
The TIDE is one of series of federal security databases created after 9/11 attacks. The database system has been criticized in the past for being too cumbersome, especially in light of an attempted attack on a plane in 2009, Reuters writes.
Tamerlan’s name got into that database when he left the United States for Russia in January 2012 but no alarm was raised, allegedly because the FBI had not identified him as a threat after the interview.
Sean Joyce, deputy director of the FBI, defended the FBI’s performance in the Boston bombings at two closed hearings in Congress on Tuesday.
While government agencies declined to publicly discuss how the watch list system handled Tsarnaev, Homeland Security Secretary Janet Napolitano disclosed some details at a separate, open hearing on immigration on Capitol Hill.
“Yes, the system pinged when he was leaving the United States. By the time he returned, all investigations – the matter had been closed,” Napolitano told the Senate Judiciary Committee on Tuesday.
Republican Senator Lindsey Graham insists that law enforcement should have kept a closer eye on the suspect after the FBI spoke to him two years ago. The FBI should also have realized last week following the bombings that he was in databases, Graham told reporters.
“After the bomb went off, don’t you think one of the first things the FBI would do is say, ‘Have we interviewed anybody in the Boston area that may fit the profile of doing this?’ How could his name not pop up, the older brother? And when you have the photo the whole world is looking at, how could we not match that photo with him already being in the system?” Graham said.
The news come the next day after the other suspect, Dzohkhar Tsarnaev old the police on Monday that Tamerlan Tsarneav organised the crime as he wanted to defend Islam from attack.
The preliminary evidence from Tsarnaev makes think that the brothers were apparently not involved with Islamic terrorist organisations.