On Saturday, Lifetime's new movie, "Chris Watts: Confessions of a Killer," will explore the true story of the crimes committed by the Frederick, Colorado, resident on Aug. 13, 2018. At that time, Watts killed his pregnant wife, Shanann, and their two young daughters, Bella and Celeste. 

The Lifetime movie will show the "revealing the months that led up to the horrific crime and piecing together the mysterious motives that made this doting father turn into a cold-blooded killer," reveals the network's synopsis. In the cast photo below, Sean Kleier can be seen as Chris and Ashley Williams as Shanann.

Chris Watts Lifetime movie Cast of Lifetime's "Chris Watts: Confessions of a Killer" Photo: Lifetime/Chris Reardon

Here's what viewers should know ahead of the Lifetime movie premiere:

While it remains to be seen how faithful the Lifetime movie will be to the true-crime case, the real story started in 2018 when police were alerted that three people, a pregnant mom and two young girls, were missing. In response, Watts agreed to do TV interviews where he expressed concern about the whereabouts of his family members.

Watts eventually pleaded guilty to the crimes. Leading up to his admission of guilt, he reportedly exhibited "significant signs of deception," which led some to question how much he knew about their disappearance. After telling investigators that he had been the one responsible for killing his family, he was given five consecutive life sentences at a Wisconsin prison without the possibility of parole.

Following the admission, new information has continued to come to light pertaining to what happened on the day of the murders.

While behind bars, Watts began writing letters to author Cheryln Cadle. In the written correspondence, he revealed previously-unheard details of what he says took place.  He also revealed that he believes a "darkness" in him contributed to the murders. The letters would eventually be published in her book, "Letters From Christopher: The Tragic Confessions of the Watts Family Murders."

READ: Chris Watts Update: Investigator, Detective Discuss Dealing With Trauma A Year Later

Since then, many have taken a closer look at the story in order to learn more about why some men become "family annihilators" and discussed his psychology in subsequent interviews. 

As for Watts' life in prison, some have reported that he feels as though he is in "his own private hell" at the penitentiary. However, he has reportedly continued to receive "female admirers" and has revealed that he partially blames his former mistress, Nichol Kessinger, for the crimes.

"Chris Watts: Confessions of a Killer" will premiere Saturday, Jan. 25, at 8 p.m. EST on Lifetime.

Chris Watts Men Chris Watts is pictured in court for his arraignment hearing at the Weld County Courthouse on Aug. 21, 2018 in Greeley, Colorado. Photo: Getty Images/RJ Sangosti