The security official with the Anti-Extremism Center, a federal agency under Russia's Interior Ministry, confirmed the Russians shared their concerns. He said that Russian agents were watching Tsarnaev, and that they searched for him when he disappeared two days after the July 2012 death of the Canadian man, who had joined the Islamic insurgency in the region. The official spoke only on condition of anonymity because he was not authorized to speak to the news media.
Security officials suspected ties between Tsarnaev and the Canadian — an ethnic Russian named William Plotnikov — according to the Novaya Gazeta newspaper, which is known for its independence and investigative reporting and cited an unnamed official with the Anti-Extremism Center, which tracks militants. The newspaper said the men had social networking ties that brought Tsarnaev to the attention of Russian security services for the first time in late 2010.
President Barack Obama said Tuesday at a news conference that the U.S. counterterrorism bureaucracy "did what it was supposed to be doing" before the Boston Marathon bombing as his top intelligence official began a review into whether sensitive information was adequately shared and whether the U.S. government could have disrupted the attack.
"We want to go back and we want to review every step that was taken," Obama said. "We want to leave no stone unturned. We want to see, is there in fact additional protocols and procedures that could be put in place that would further improve and enhance our ability to detect a potential attack."
In Rhode Island, DeLuca said Tamerlan Tsarnaev's widow met with law enforcement "for many hours over the past week" and will continue cooperating. FBI agents on Monday visited her parents' North Kingstown, R.I., home, where she has been staying, and carried away several bags.