Arrest him, take him to the US. Have him walk down the street with very minimal "security" personnel to "protect" him until he gets to the courthouse. Then a civilian will of course kill him. And of course the civilian would be found innocent by the jury. Problem solved AND it makes the US look good since they could say that they were going to give him a fair trial.
The government wouldn't be behind the attack. The civilian would do it on his/her own accord, simply because he/she's would be good person and everyone wants to kill Osama.