WASHINGTON - Dzhokhar Tsarnaev, one of two brothers accused of bombing the Boston Marathon, told investigators that the pair had originally planned to mount an attack on the Fourth of July, a U.S. counterterrorism official said Thursday.
Meanwhile, another counterterrorism official said that Russian intelligence officials believe Tamerlan Tsarnaev, the elder of the two brothers, may have met with militants while living in a Russian province in 2012.
Authorities have scoured the background of the 26-year-old Tamerlan Tsarnaev for potential sources of radicalization in the years leading up to the bombings that left three dead and more than 260 wounded. They have focused on the six months he spent in Dagestan, a region in southern Russia.
Russian authorities had warned the FBI and CIA in 2011 that Tsarnaev might have ties to radical Islamist groups.
"It looks like there was some interaction," one counterterrorism official said of the 2012 visit. "It doesn't seem like it was involving logistics or planning. They certainly weren't working with him because they were focused primarily on the traditional Russian enemy."
The official, who requested anonymity because he was not authorized to speak about the investigation, added, "There is no evidence of pre-operational planning or training or even that this was a source of his radicalization."
The official who revealed the original target date of the Fourth of July also said that Russian intelligence told U.S. officials that Tamerlan Tsarnaev met with an Islamic militant at a mosque in Dagestan last year. There is no evidence he got bomb training there, the official said.
By the time Tamerlan Tsarnaev arrived back in Boston in July 2012, his views on Islam had grown more conservative.
He died after a gunbattle with police in Watertown, Mass., on April 19, and Dzhokhar Tsarnaev, 19, was arrested.