Since the suspect died in a shootout with the police, we may never know for sure whether his motive was political (the definition of “terrorism”). Material from extremist political groups like Nazis (or Daesh, etc.) could strongly suggest a political motivation, but political extremists could get violent for non-political reasons. (Of course, if he left a note or other evidence showing political motivation for that act, then it would be much more certain to be terrorism.)
The way life used to be in the late 1980s and early 1990s included crime rates (including homicide rates) much higher than they are now.