Well they were devil worshippers alright..and I'll bet Jesus was upset with that.
Maybe they were. Maybe they had simply been spending a lot of time playing with a ouji board; or tarot cards; or astrology; or maybe they were playing which. Maybe not. But I would expect something of the sort after such a crime. This is very often the case.
I am curious about a possible connection. It interest me that there so often is one.
I am *Not* saying any of this will *make* a person violent. At their age, I was pretty heavily into the occult myself.
I do think overt Satanism leads to cruelty and killing. And, IMO, any occultic activity can be dangerous and destructive to the person, as well as those around them; even tho it rarely leads to anything like this murder.
As for your quip about Jesus being upset. . .
I am sure He is; as is everyone who cares about these murderous girls, and the girl who died.