Alleged Boston Marathon bombing suspect Tamerlan Tsarnaev's name was included on two U.S. terror-watch databases in 2011 after Russia separately requested assistance from the FBI and the CIA to investigate his possible ties to Islamic extremism.
Tsarnaev was included in a database in the spring of 2011 as the FBI tried to determine whether he had conducted any foreign travel.
Later that year, the CIA requested that his name be added to the broader general terror database out of what a U.S. official called "an abundance of caution." But it was later determined that the names and dates of birth provided by Russia to the CIA were all incorrect.
U.S. officials say that in March 2011, Russia's intelligence agency, the FSB, contacted the FBI requesting that it investigate Tsarnaev's possible ties to extremists. The FBI was able to determine Tsarnaev's correct identity after realizing that the name provided by Russia was inaccurate.
Several months later, the FBI closed its investigation of Tsarnaev after determining that he did not pose a threat. But U.S. officials say they never received a response from the Russian spy agency about their conclusion.
According to a U.S. security official, as part of their investigation, the FBI included Tsarnaev's name in a database called TECS -- the Treasury Enforcement and Communication System -- to determine whether he had traveled out of the country. It turned out he had not. Entries into this database remain active for only a year.
This is the database that Homeland Security Secretary Janet Napolitano told a Senate panel Tuesday had "pinged" when Tsarnaev left the United States in January 2012 on a six-month trip to Russia. The trip has been a focus of speculation that Tsarnaev might have made contact with or received terrorist training in the Dagestan region where he was visiting relatives.
The U.S. security official explained that the positive hit when Tsarnaev left the United States resulted in the Joint Terrorism Task Force's being notified that he had left the country. It is unclear which federal agency within the task force would have actually received the notification of his travel and what was done with the information.
By the time Tsarnaev had returned to the United States in June 2012, the TECS database entry had already expired.
In late-September 2011, the CIA received a similar request from the Russian intelligence agency for an investigation of Tsarnaev and provided two variations of his name and two possible dates of birth, which was pretty much the same information provided to the FBI six months earlier.
A U.S. intelligence official says the CIA "then nominated him for inclusion in the watchlisting system and, given his status as a U.S. person, shared the information with the appropriate federal departments and agencies specifying that Tsarnaev may be of interest to them."
Among the federal agencies contacted were the National Counterterrorism Center (NCTC), the Department of Homeland Security, the State Department and the FBI.