camera to executing a prisoner who had just been released in afghanistan. >> reporter: shortly after releasing the taliban detainee, he took matters into his own hands. did you can kill the taliban bomb making? >> yes. >> reporter: that led them it to reopen the investigation in the killing and ended up charging him with murder. he was awaiting trial until for what could possibly be the first time in american history, as far as we can tell, the american chief pardoned a member of the armed services accused of a war crime prior to their trial. and he pardoned army lieutenant clint lawrence who was serving time for ordering his soldiers to fire on unarmed men. and he was testified against by