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 has been president of syria since the year 2000. Thats 16 years in power. The syrian army led by assad is in a constant battle with armed rebel militants who are taking hold of syrian cities and towns. Assads technique is to bombard these towns in order to force syrian populations out of the area. A poor tactic but does that make him a terrorist? Who is funding ISIS and all of the other militia groups. America have been proven to be funding the militia groups, just as they have been doing with the Al qaeda since back in the world war. Lets look at the root of the problem.
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.