You’ve got the evidence, convict him, THEN question. If he hesitates, note that Americans were victims of the terrorist attack and extradition is on the table. He’s got the option of fully cooperating with authorities, or taking his chances on the US courts.
Might as well be the boogy-man before word gets everywhere about how well we treat terrorists.
Transfuse him with pigs blood
Give him sex change
sell him to east asian brothel frequented by fat german tourists
Buy him back 5 years later and dump him nude in downtown Riyahd
Is that supposed to scare him? No execution possible and probable refusal by the DOJ to prosecute - no probable cause crap from Lynch, at Obama's direction.