One of the most shocking murder cases to ever exist is being reopened on CBS.

On Tuesday, a trailer was released for The Case of JonBenet Ramsey, which will be a six-hour docu-series about the child whose murder was never fully solved. This comes 20 years after the 6-year-old's death.

The trailer starts off with a chilling 911 call about Ramsey and how there's a note involved. It then moves into a child walking to her Christmas tree. The girl's father is then seen where he tells the public that he did not kill his daughter.

The trailer gets more chilling with how no one ever found out who killed JonBenet, but maybe that can finally change. There are also some graphic scenes that appear to be from the scene of the crime.

An FBI investigator is working on the case who seems to know what he's doing. He'll be joined by a behavioral analyst who will "try to get to the bottom of this."

Others are going to delve into this mystery while looking at all the evidence to see what actually went down on December 26, 1996. Theories go back and forth among the group of investigators who may be able to solve the case with the clues.

A house is even getting rebuilt so everyone can walk through and pinpoint every move.

The important thing is to "get the truth out so that JonBenet can rest in peace."

Check out the trailer below.

The Case of JonBenet Ramsey premieres on Monday, September 18 on CBS.

Tags: JonBenet Ramsey