Chris Watts' prison pen pal - a married grandmother of 12 - reveals she was drawn to his 'boyish demeanor' and continued writing to him even after he admitted to 'daydreaming' about killing his wife Shanann

A prison pen pal of killer husband Chris Watts has offered chilling new details about the letters they exchanged - revealing that he'd fantasized about murdering his pregnant wife long before he went through with it.  

Cherlyn Cadle, 67, appeared in a new episode of Lifetime's Cellmate Secrets to share personal details from letters she exchanged with Watts - a Denver man convicted of murdering his pregnant wife Shanann and their two daughters in 2018.

Cadle, a Midwest author and grandmother of 12, asserted that the murders were premeditated based on what he'd told her from behind bars.  

'He told me he would daydream about killing Shanann,' Cadle said. 'She would be yelling at him or be upset about something and he wouldn't fight back, but he would just stand there and just daydream about what it would be like to kill her.'

Cadle told Fox News she wrote to Watts in prison after watching his first interview on TV. 

'When I saw his first interview, I don't know, I looked at him that morning and I just felt something really spoke to me,' she said. 'It was like a calling for me to contact him and see if he would share his story with me.'

Cherlyn Cadle, 67, appeared in a new episode of Lifetime's Cellmate Secrets to share personal details from letters she exchanged with family killer Chris Watts

Watts was convicted of murdering his pregnant wife Shanann and their two daughters Bella and Celeste in 2018 

Cadle wrote her first letter to Watts in February 2019. In a matter-of-fact tone, she laid out her intentions to write a book, saying she had never been in doubt of his guilt. Eventually they built up a correspondence, with Watts telling her about his life and the murders. Pictured: Watts writing to Cadle in April 2019

'I knew he was guilty. You could tell by the way he was talking, the body language,' Cadle added. 'But it was just one of those things where I really felt like I was supposed to do it.' 

Watts eventually replied to Cadle after her third letter at the beginning of 2019. 

'He was receptive from the very beginning,' Cadle recalled. 'He said that God told him to respond. I think because I was a mother and grandmother, he didn't feel any kind of threat.'  

When Watts sent her a 12-page letter outlining details of each murder, Cadle immediately grew emotional.  

'I just broke down and started bawling,' Cadle admits. 'I cried and cried. I just couldn’t believe what he did to those girls… It was a real shock to read his letter.' 

'I knew in my heart right then and there that this was the real and true confession. He said it was planned right away,' she added.  'It was premeditated. And he wanted to clear the slate. He wanted to start over. He didn’t want to bring any baggage into the new relationship. And there was a good-sized insurance policy… It changed everything for me.'

Calde also mentioned that Watts was already getting a 'lot of fan mail from women who were sending him pictures of themselves in bikinis' who stated their love for him.   

After exchanging multiple letters and speaking to him on the phone several times a week, Cadle agreed to meet Watts in prison. 

'I hate to even admit this because he is a murderer and what he did is so horrendous, but when I first met him, he had this boyish demeanor,' she said. 'He was gentle, soft-spoken and just appeared as a nice guy. And he remained that way throughout our communications. That changed when he started talking about the murders.'

The letters came pouring in after Watts, 36, was convicted of murdering his entire family in August 2018. 

First, he strangled his wife Shanann, who was 15 weeks pregnant with their son, inside their Frederick, Colorado home before smothering their daughters, Bella, 4, and Celeste, 3.

Watts disposed of their bodies at an oil drilling site where he worked, hiding behind the charade of the concerned husband and father concerned about his family's whereabouts. 

When investigators discovered Watts had been having an affair with a woman he worked with, he became the prime suspect in his family's disappearance.  

When investigators discovered Watts had been having an affair with a woman he worked with, he became the prime suspect in his family's disappearance

The Fredrick, Colorado residence where Watts murdered his wife Shannan and their two daughters, Bella and Celeste, before disposing of their bodies at an oil drilling site

The bodies were eventually discovered, and Watts was arrested before pleading guilty to their murders. 

Watts' mistress, Nichol Kessinger, penned a book about her involvement in the case entitled Letters from Christopher: The Tragic Confessions of the Watts Family Murders.

In the book Watts admits he would not be in prison if it was not for Kessinger. 

'If I had not met Nikki, I would never have killed my family,' he told Cadle in letters and interviews for the book.  

Watts also claimed to still love Kessinger, who he had been seeing for two months before decideding to murder his entire family. 

'He was mesmerized by her,' Cadle told DailyMailTV in an exclusive interview in 2019. 'She showed him respect that he didn't feel like he'd ever been shown before.' 

As part of her research, Cadle spent 15 hours meeting face-to-face with Watts in prison, had phone calls three times a week and exchanged dozens of letters. 

Even though Kessinger 'never asked him to get rid of his family,' authorities speculated that Watts wanted a fresh start with his mistress and believed their relationship may have 'contributed' to his actions. 

In exchange for pleading guilty, prosecutors agreed not to pursue the death penalty. Watts was later sentenced to life in prison without the possibility of parole.

The Cellmate Secrets episode, narrated by Angie Harmon, airs on Friday at 10pm EST. 

Watts was having an affair with Nichol Kessinger (pictured together) when he killed his wife