So, you're calling him a terrorist OR you're believing the story that he shot these people over parking spots.
Terrorists don't have to political motives behind them. But, if you want to make it up, I guess they can.
Terrorism - the use of unlawful or threat of unlawful violence to coerce governments or societies in the pursuit of goal that are generally political, religious, our ideological.
That's the word you should have defined. It's the context phiilyb alluded to.