McG, suppose he had been handed over to some such country as Canada.
He would be guilty of no crime there.
No charge could be brought.
What would they do with him.
His only ambition in life is to kill westerners.
Any foster family would be likely to all wake up dead one morning.
Would you have him stay with your family?
A care home would be the same opportunity for him.
He would need to be kept secure but legally he could not be.
Any more suggestions Kevin?