Quote Originally Posted by Breukelen advocaat
He's got a 25 million dollar bounty placed on his head by the FBI, for things he did prior to 9/11. FBI Ten Most Wanted Fugitive - Usama Bin Laden

As far as "evidence": He was not there - but he freely admits to being responsible for it, in films and other media sources.
Actually, was he Osama?

Expert Goes On Record: Bin Laden 9/11 Confession Is Bogus

Not trying to defend Osama, but I don't believe he was behind 9/11. In other interviews other than the tape that "he" confessed on (look at that link) he has claimed innocence and proclaims that attacking women and children is against Islamic Jihad law.