Chris Watts Update 2019: Killer Reveals Mistress, 'Darkness' Inside Him Contributed To Crimes

Colorado resident Chris Watts is currently serving five life sentences for killing his pregnant wife Shanann and their two young daughters, Bella, 4, and Celeste, 3, on Aug. 18, 2018. While details surrounding the crimes remained obscured for quite some time, Watts recently revealed his truth to 65-year-old Cheryln Cadle for her new book "Letters From Christopher: The Tragic Confessions of the Watts Family Murders."

According to the Daily Mail, Watts, 34, revealed to Cadle that he believes his former mistress Nichol Kessinger played a big part in his crimes. "If I had not met Nikki, I would never have killed my family," he told the author during their correspondence.

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

As for why the Frederick, Colorado resident felt such a pull towards Kessinger, Cadle told DailyMailTV that Watts had been "mesmerized by her" because "she showed him respect that he didn't feel like he'd ever been shown before."

Watts also revealed that he has wondered where Nichol currently is and if certain letters and postcards he's received while in prison have secretly been from her.

Additionally, he also explained his thoughts immediately following the horrific Aug. 2018 crimes. "The darkness inside of me had won, it was still in me, though, I thought maybe permanently. I felt evil, swallowed up by this thing inside of me. I felt like I could kill anything and be justified for doing it," he said.

Ultimately, Cadle and Watts exchanged dozens of letters and met several times leading up to the completion of her book. However, he stated that the only way he would allow Cadle to use those letters in her book is if she also included his "testimony of coming to God and the forgiveness he received." Watts is not set to take any of the money made by book sales for himself or his family.

Watts' everyday life in prison has been described in several conflicting ways over the course of his incarceration since committing the crimes, as some have said he is in "his own private hell" while others have said he continues to receive mutiple "female admirers."

"Letters From Christopher: The Tragic Confessions of the Watts Family Murders" will be released on Oct. 7.