Updated 6:05 p.m. ET
A Republican senator says the name of Tamerlan Tsarnaev - the suspect in the Boston Marathon bombing who died in a firefight with police - was misspelled on his 2011 trip to Russia.
Sen. Lindsey Graham, R-S.C., said Tsarnaev's correct name never went into "the system," and thus thwarted the FBI in discovering the six-month trip. Graham said on Fox News that he spoke to the assistant director of the FBI on Sunday night.
"He went over to Russia but apparently when he got on the airplane, they misspelled his name, so it never went into the system that he actually went to Russia," Graham said.
Graham's spokesman, Kevin Bishop, confirmed the senator's comments on Monday.
The trip is the subject of the investigation into last Monday's deadly bombings.
After criticizing the FBI over the weekend, Graham eased off a bit Monday, saying "the FBI did a good job."
"One of two things happened ... the FBI either dropped the ball or our system doesn't allow the FBI to follow this guy in an appropriate fashion. I think once the Russians made the request, the FBI did a good job of looking at him. The reason we didn't know he went to Russia is because the name was misspelled," said Graham.
Rep. Mike Rogers, chairman of the House intelligence committee, had said Sunday on NBC that Tsarnaev may have used an alias to travel to Russia.
"I think all of us are wondering, if the Russians told us about this guy being a radical Islamist in 2011, how could we have missed it," Graham said told reporters in a press conference later. "Here's the question we all should be asking: Let's assume for a moment the FBI made a diligent effort to make an investigation based on the Russian information and, quite frankly, from what they told me... they did. But, how could we, from 2012 until the attack, miss all of the radical statements and activity this guy engaged in, the older brother, on the Internet and the YouTube videos?"