Casual amateur analysis might conclude this murder was politically motivated. It may well be! BUT !"Report reveals Evergreen High School shooter's alarming online activity linked to violence, white supremacy" #180
Does it make sense to assume it?
If the shooter decided what was missing from his own life was the excitement of being the target of a manhunt,
and realized murdering a non-celebrity might reduce his own publicity yield,
and this particular celebrity was nearby (no need to deal with the TSA)
wouldn't acting on that scenario produce similar behavior?