since criminal charges are involved basically what is going to happen is:

1. they can try him based on the evidence that they have from witnesses and so on and he will be found innocent or guilty solely based on that. If the witnesses and evidence point to his guilt and he does not remember it may turn out he was innocent but without his testimony and eveidence locked up in his brain he may end up in prison, which is why his lawyer and everyone is pressing him to remember. If he really is innocent of the charges he deserves to be free not locked in prison due to lack of evidence that points to his innocence.

without his remembering he could also be deemed incompetent to stand trial. if That happened he will not be release. He will be sent to a prison or security type mental facility until he is deened competent to stand trial, meaning either he remembered the situation or the doctors feel he can go through with trial without memory and take his chances of being convicted or not based on what the prosecution and defense already has.

It would be in his best interest to "remember" and as soon as possible. Mental facilities are not places you want him to spend possibly the rest of his lifetime because no one can say for sure that he won't commit the same crime again expecially when he can't remember what happened to set him off the first time if he committed the crime and they will assume he did without his remembering the situation.