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Motivations behind suspect Tamerlan Tsarnaev's attacks are still unknown. But, his boxing trainer says he knows why he might have done it.
The former boxing trainer of Tsarnaev, John Allan, says he was "frustrated" with citizenship rules. Former CNN reporter and Entertainment Tonight host, Rob Marciano, speaks to Allan.
We've seen him on surveillance video, but we've rarely heard him. Watch and listen to newly discovered video of Dzhokhar Tsarnaev.
The video, posted on Twitter in March, shows Boston Marathon bombing suspect Tsarnaev playing with his niece.
The mysterious killing of an 8-year-old girl has shaken a small community in California. CNN's Paul Vercammen reports.