re: What is the most chilling unsolved murder mystery you know?

No he was at the very bottom of the bodies. The guy stacked everyone 2x2 3 stacks high then shot down into them. Then stabbed the survivors until his knife broke. He then laid everyone down in the blood and realized the one guy was alive. The guy said "I can't identify you" and the killer said "imma let you live big man" and left.
There were other survivors just one unhurt. He was as able to identify him as black and that he said he was an ex cop who was fired and had nothing to lose.

I actually looked into every story posted.

The yuba 5 I think we're just too mentally ill to make the decisions needed to survive after being lost.

The hotel Cecil girl was a schizo.

But the others.... some crazy mysteries there.