Well, I first speculated it was the Saudis that did this in revenge for Hariri...
But now I have to think who could do it easier than the Iranians themselves?
Why would the Iranians kill him? He could have backstabbed them on a money deal, opium trade, even some personal insult. These group operate and think like mafias.
9/11 Shermy.... according to info Ken Timmerman has and has discussed ....Imad escorted the muscle hijackers....across Iran.... PRIOR to the strike.