NEW YORK (AP) — Investigators are looking into whether suspected Boston Marathon bomber Tamerlan Tsarnaev, who spent six months in Russia's turbulent Caucasus region in 2012, was influenced by the religious extremists who have waged an insurgency against Russian forces in the area for years. Tamerlan and brother Dzhokhar have roots in Dagestan and neighboring Chechnya but had lived in the U.S. for about a decade.
U.S. officials described to the AP what the government knew about Tamerlan since he was first placed on the intelligence community's radar 18 months ago. The officials spoke on condition of anonymity because they were not authorized to publicly discuss the ongoing investigation:
— Russia's internal security service, the FSB, sent information to the FBI about Tamerlan Tsarnaev on March 4, 2011. The Russians told the FBI that Tsarnaev was a follower of radical Islam and had changed drastically since 2010. Because of the subsequent FBI inquiry, Tsarnaev's name was added to a Homeland Security Department database used by U.S. officials at the border to help screen people coming in and out of the U.S. That database is called the Treasury Enforcement Communications System, or TECS.
— The FBI's Boston office opened a preliminary review of Tsarnaev and searched government databases for potentially terror-related communications. Investigators looked into whether Tsarnaev used online sites that promoted radical activity. They interviewed Tsarnaev and his family members but found nothing connecting him to terror activity. The FBI shared that information with Russia and also asked for more information on Tsarnaev, but never heard back. The FBI's review into Tsarnaev was closed in June 2011.
— In late September 2011, Russia separately contacted the CIA with nearly identical concerns about Tsarnaev. The Russians provided two possible birthdates for him and a variation of how his name might be spelled, as well as the spelling in the Russian-style Cyrillic alphabet. The CIA determined that Tsarnaev should be included in the Terrorist Identities Datamart Environment, known as TIDE, and the National Counterterrorism Center added it into the database. The spelling of Tsarnaev's name in TIDE was not the same as the spelling the FBI used in its investigation. The CIA also shared this information with other federal agencies in October.
— In January 2012, Tsarnaev traveled to Russia and returned to the U.S. in July. Three days before he left for Russia, the TECS database generated an alert on Tsarnaev. That alert was shared with a Customs and Border Protection officer who is a member of the FBI's Boston joint terrorism task force. By that time, the FBI's investigation into Tsarnaev had been closed for nearly six months because the FBI uncovered no evidence that he was tied to terror groups.
—On Jan. 21, 2012, the airline on which Tsarnaev was traveling misspelled his name when it submitted its list of passengers to the U.S. government for security screening. Airlines are required to provide the list of passengers on international flights so the U.S. can check their names through government databases, including the terrorist watch list. Because his name was misspelled, there was not another alert like there was three days earlier.
— In July 2012, Tsarnaev returned to the U.S., and another alert was generated in TECS. This information was again shared with the Customs and Border Protection officer on the FBI's Boston joint terrorism task force. But because the FBI had closed its investigation into Tsarnaev a year earlier, there was no reason to be suspicious of his travels to Russia.