I'm Lester Holt. Tonight on Dateline, a famous crime novelist returns to an infamous case.

It had so much mystery involved, panagrams painted on the wall. What was this young man doing in that tunnel?

The Mastatown. Yeah, is a pretty horrible place to die.

The murder happened on the summer solstice. This whole occult story came out.

There's evidence of occult activities having taken place up there before.

He told me that he had witnessed a murder.

Well, I'm a bleeding.

And that he was helping the police with it.

Little by little it started coming out.

There had been some plot, a foot.

Brutal and violent and chaotic. They are vicious killers.

It was a horrible betrayal.

Here's Keith Morrison with night of the summer solstice.

This wasn't supposed to happen, ever.

It was a chilly December morning, 2020. The high desert outside Los Angeles.

In there behind barbed wire and secure locks and thick concrete, a prisoner was placed in front of a camera.

It was a parole hearing. For a lifer who was never supposed to be set free.

50 miles away, nervous and worried, the sister of the man's victim listened to a live broadcast.

With her, a storied LA homicide detective now retired, named Rick Jackson.

A powerless intervene. They waited for the board's decision.

And it all came flooding back. As if decades advanced.

And the strange, terrible events had only just occurred.

...