Dzhokhar was wounded in the shootout with police as he and his brother made their getaway attempt. He is charged with using a weapon of mass destruction to kill, a crime that carries a potential death sentence.
Russian agents placed the older suspect under surveillance during a six-month visit to southern Russia last year, then scrambled to find him when he suddenly disappeared after police killed a Canadian jihadist, a security official told the AP.
U.S. law enforcement officials have been trying to determine whether Tamerlan Tsarnaev was indoctrinated or trained by militants during his visit to Dagestan, a Caspian Sea province that has become the center of a simmering Islamic insurgency.
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.