Yes, I think that there is strong evidence that Assad is a terrorist and attacked his own people in Syria. He also has done nothing to help is own people, and may have used their own weapons against them. In this case, I think Assad should be tried for his crimes internationally.
A true leader should value the opinions and quality of life of those he/she leads. Assad's extreme actions taken against pro-rebel protestors, leaves a lot to be desired. He is purported to be involved with the Arab Spring Movement. In my opinion, the fact that the United States has asked that he step down as President, does make me wonder about his motives.
Assad is not a petty terrorist, but a mass murderer with do regards for human life. He is one of the worst leaders in the middle east, and the UN has not done enough to put at end to his brutal tyranny and to help the Syrian people get a government that actually cares about them.