The name of one of the Boston Marathon bombing suspects, Tamerlan Tsarnaev, was listed on the U.S. 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 automatically kept close tabs on him, sources close to the bombing investigation said on Tuesday.
The sources said Tamerlan Tsarnaev's details were entered into TIDE, a database maintained by the National Counterterrorism Center, because the FBI spoke to him in 2011 while investigating a Russian tip-off that he had become a follower of radical Islamists.
Tsarnaev, 26, was killed in a police shootout early Friday, while his younger brother Dzhokhar, 19, was captured later that day. Prosecutors say the brothers, ethnic Chechens who had been living in the United States for more than a decade, planted two bombs that exploded near the finish line of the marathon on April 15, killing three people and wounding more than 200.