They're criminals. Yes, criminals are bad too you know.
Terrorism is the threat or purposeful use of physical force specifically against non-combatants for the purpose of instilling fear in a population and thereby effecting political change.
Everything else is just plain old crime, no matter how horrid it is.
Of course that's no fun for all the alphabet agencies, so terrorism will be whatever they say it is. And that's why the PA is so dangerous.