Lori Vallow and her husband, Chad Daybell, have faced quite a bit of suspicion following the disappearance of her children, Tylee Ryan and Joshua "JJ" Vallow. After police returned to Daybell's Idaho property on June 9, the remains of Vallow's children were recovered. Subsequently, Daybell was taken into custody and charged with two counts of destruction and alteration or concealment of evidence, which are felony charges.

Now, ahead of his upcoming jury trial, the couple's former best friend is breaking her silence on a new episode of "Dateline" with NBC correspondent Keith Morrison.

On Monday night's episode, Melanie Gibb will discuss her experiences with both Vallow and Daybell for the first time on network television.

READ: Lori Vallow Update: Discovery Of Tylee, JJ's Remains Prompts Discussion About Chad Daybell's Defense

When speaking to Morrison, Gibb is asked why she had not previously spoken out about what had transpired. To this, she says that she didn't want the media to see her due to the fact that her friends were being referred to as murderers. Later, she is asked whether or not she felt betrayed by the couple. "Oh, yeah," she responds, adding that they had tried to use her as "their way of escape."

Continuing, she added, "So, part of me is processing, 'I can't believe you're friends with these people.' The other part of me is like, 'How did you even believe any of the things they shared to you?'" The clip can be seen below.

Additionally, the new episode of "Dateline" will take a more comprehensive look at the chain of events leading up to Vallow and Daybell being taken into custody. In a preview of Monday's episode, which can be viewed below, others can also be seen discussing the case. As stated by someone close to the pair, when asked where Vallow's children were, Daybell once allegedly said, "For your safety, I cannot tell you."

Aside from Gibb's new interview, she additionally spoke out in a written account of what she says took place prior to the disappearance of Vallow's children. At that time, she stated that she believed Daybell had "opened the doors of darkness." However, she is not the only person in recent months to shine a light on the "strange" behavior of the "prolific Doomsday author, alleged cult leader and former grave digger," including the fact that he had allegedly believed he would not have to face consequences.

READ: Lori Vallow Update: Chad Daybell's 'Deception' Revealed After Tylee, JJ's Remains Found On Idaho Property

As for where Daybell's case currently stands, after appearing before a judge to learn that his bail had been set at $1M, he entered a not guilty plea. His next court hearing is scheduled for July 1.

The new episode of "Dateline," called "What Happened To JJ and Tylee," will air Monday night at 10 p.m. EDT on NBC.

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"Dateline" key art is pictured. NBCUniversal
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