This professor was, no doubt, killed by the iranian regime,as a member of the opposition.Firstly, the regime has made it clear that members of the opposition would be harshly dealt with. There is no reason to believe that they don't intend to do exactly this. Secondly, the regime is using the centuries old practice of deflecting blame to the Jews. this is very obvious to anyone with a sense of history.
India hangs only man sentenced to die for 1993 Mumbai blasts (AP)
from the article: Iran: Israel, U.S. killed pro-Mousavi nuclear scientist