This was obviously a heinous act, but I think calling it terrorism is a bit of political pandering.  One of the many key components that makes something terrorism is premeditation.  It's done with a specific purpose in mind -- to terrorize.

The prosecutor charging this as 2nd degree murder suggests they have no evidence to show it was premeditated (pre-planned).  That makes "terrorism" an inaccurate description of it, IMO.  A monsterous act of rage, yes.  That should be punished to the full extent of the law.  But not terrorism.