Here's the latest on the Tsarnaev brothers:
Accused Boston bomber Dzhokhar Tsarnaev has told FBI investigators that he and his brother were operating alone and did not receive assistance from outside terrorist groups, officials said Tuesday.
....Investigators separately have tentatively concluded that his older brother, Tamerlan Tsarnaev, 26, who died early Friday morning after a shootout with police, did not meet with Islamist militants during his six-month visit to Russia last year, according a senior U.S. counter-terrorism official.
Experts say the brothers increasingly appear to have been self-radicalized “lone wolf” operators who worked independently, using bomb recipes gathered from websites.
I'm not really sure what this means, and obviously Dzhokhar might be lying. But apparently the current state-of-the-art thinking among interrogators is that the Tsarnaevs were motivated by "extremist Islamic beliefs"—specifically by "the American wars in Iraq and Afghanistan"—but acted on their own.
There sure is something odd about that six-month trip to Russia, though. The story we've been told is that the Russians warned the FBI back in 2010 that Tamerlan might be connected with Islamic radicals. The FBI checks it out and finds nothing. Then Tamerlan goes to Russia in 2012. So what happened then? Did the Russians track him while he was there? If so, did they pass anything further along to the FBI? If not, why not? They're the ones who were supposedly convinced that Tamerlan was up to no good. So what happened?