An inspector general's report has revealed that Russia withheld important information relating to the radical-Islam background of one of the Boston Marathon bombers, that could have potentially prevented the attack that killed three people and injured over 260 in April 2013.
One of the suspects, Tamerlan Tsarnaev, was a "follower of radical Islam and a strong believer" and had "changed drastically since 2010 as he prepared to leave the United States for travel to the country's region to join unspecified underground groups," the Russian government shared with the FBI in 2011, two years before the attack.
Russian officials then declined several requests for additional information, however, which could have prevented the bombing, according to law enforcement agencies, the report said, according to The New York Times.
Tsarnvaev, who was 26 years old at the time of the incident and was killed at a later shoot-out with police, is accused of carrying out the bombing with his younger brother, Dzhokhar Tsarnaev, 19 years old at the time, who was injured by police but survived and is awaiting trial, facing the death penalty if convicted.
The brothers are ethnically from Chechnya, a federal subject of Russia, but they lived for the better part of the last decade in America. Multiple reports came out last year linking them to a mosque in Boston which had been visited by radical Islamists and convicted terrorists.
"We don't know where these boys were radicalized, but this mosque has a curriculum that radicalizes people. Other people have been radicalized there," said Charles Jacobs from Americans for Peace and Tolerance in April 2013. The interfaith group investigated the Islamic Society of Boston mosque in Cambridge, Mass., which the Tsarvnaev brothers attended.
The inspector general said in his new report that only after the bombing did Russian authorities share with the FBI a phone call between Tamerlan Tsarnaev and his mother, in which they reportedly discussed Islamic jihad.
"They found that the Russians did not provide all the information that they had on him back then, and based on everything that was available the FBI did all that it could," a senior American official briefed on the review revealed.
Authorities have not found evidence that the brothers belonged to any international terrorist organization, however, with a senior official describing them as "homegrown violent extremists."
"We certainly aren't in a position to rule anything out, but at this point we haven't found anything substantive that ties them to a terrorist group," the official said.
Another official said that had they known the additional information, authorities could have investigated Tsarnaev further, though whether that would have uncovered the plot remains up for debate.
With the one-year anniversary of the bombing coming up, The Los Angeles Times said in another report on Wednesday that Tamerlan Tsarnaev attempted three months before the attack to legally change his first name to "Muaz," in tribute of a well-known Dagestan rebel killed by Russian forces in 2009.
Officials believe the older brother was radicalized during his 2012 visit to Dagestan, where Islamist insurgents have been rising up against Russian forces.