CIA wanted Boston bombing suspect, Tamerlan Tsarnaev, on terrorist watch list

In the wake of the Boston Marathon bombings, new details are emerging about security concerns raised over the elder suspect, Tamerlan Tsarnaev, who was killed last week.

The Washington Post wrote that the US Central Intelligence Agency requested over a year ago that the older of the two Tsarnaev brothers be added to a database maintained by the National Counterterrorism Center. Russian authorities contacted US intelligence officials back in the fall of 2011 about Tamerlan Tsarnaev, concerned over his increasing Islamist radicalism.

The Post said that Tsarnaev's name was, in fact, added to the Terrorist Identities Datamart Environment, or TIDE, database, which also includes the Transportation Security Administration’s “no-fly” list — though it is unclear which agency added it. The CIA declined comment to the Post on the case.

The New York Times wrote of the CIA's process:

"After the C.I.A. cleared him of any ties to violent extremism in October 2011, it asked the National Counterterrorism Center, the nation’s main counterterrorism agency, to add his name to a watch list as a precaution, an American intelligence official said Wednesday."

Tsarnaev was killed last week during a confrontation with police. His younger brother, 19-year-old Dzhokhar Tsarnaev, is being treated at a Boston hospital for injuries sustained while he was being pursued by federal, state and local officials. He has been charged with use of a weapon of mass destruction and destroying property in a malicious way resulting in death.

More from GlobalPost: Joe Biden blasts Tsarnaev brothers as 'knock-off jihadis' (VIDEO)

The CIA request follows a closed FBI inquiry into Tamerlan Tsarnaev, months earlier, also based on prompting by the Russians.

On Wednesday, Vice President Joe Biden made headlines for blasting the Tsarnaev brothers at a memorial for a slain MIT officer, calling the bombing suspects "perverted, cowardly, knock-off jihadis."

Meanwhile, FBI agents have been in the Russian republic of Dagestan interviewing the Tsarnaev brothers' parents for more answers.

Their father told Russian news agency RIA Novosti that he and his wife planned to travel to the US on Thursday, though a lawyer said their plans were not final, USA Today reported.