This has nothing to do with the Joker. There have been horrible serial killers and terrorists before the Joker was ever created, and there will be more killers and terrorists in the future.
This is not new.
Yes. But we can't pretend the Joker has nothing to do with it, in some way.
We had the guy in Belgium who murdered a bunch of kids in a nursery.
The soldier who had PTSD, he went around causing havoc just so the police would kill him.
The schoolboy in the UK who tried to burn his school down.
Now this guy.
All 4 of them using the Joker as their inspiration to go out and cause havoc.
But they were obviously nutjobs before Heath's Joker appeared. Fanatics they were.