I read the letter/statement from his Lawyer. I don't think it is as simple as he knew his friend was going to murder someone and gave him a gun knowing he was going to commit a crime. Hard to know what really did go down though. If someone leaves a gun in your back seat, you are going to give it back to him at some point. Under what circumstance would it be OK to not give the gun back to its rightful owner? Is someone supposed to make a determination about whether there was intent to commit a crime before you give it back? And for how long? If you return a gun to its owner, are you culpable for an hour, a day?
Again, I am sure I don't know all the details. If it is something different than the gun being left in his back seat, if he went and got the gun from somewhere else and brought it to the crime scene, that seems different.