The piano-playing siblings appeared Thursday on Megyn Kelly Today to discuss dad Keith Brown's sexual abuse case and the new documentary about their lives

Musical Prodigy Siblings: Why We Turned Our Dad in for Sex Abuse & How We're Helping Other Survivors

A police report from that conversation, obtained by the Salt Lake Tribune, shows the Brown sisters, Deondra, Desirae and Melody, were wrestling with their moral obligation to disclose something so private.

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“Each victim told me [she feels] terrible about bringing this information forward; however, due to their father recently obtaining some young female clients where he represents them in his business, they are concerned these things may begin to occur with some of these clients,” the report stated.

The ensuing criminal case ended with Keith pleading guilty in February 2011 to a charge of first-degree felony sodomy upon a child and two counts of second-degree felony sexual abuse.

However, court and police documents cited by the Tribune show the abuse lasted at least eight years and occurred hundreds of times for one of the girls. According to the siblings (all of whom are now in their 30s) it lasted even longer and included “thousands of instances of abuse.”

Prosecutors told the Tribune in 2011 that the three charges to which Keith pleaded were characteristic of the abuse of his daughters instead of representative of every single act.

Keith remains behind bars, having been sentenced to a minimum of 10 years in prison. A judge at his sentencing labeled him a “danger to society,” according to a previous PEOPLE report.

His current attorney did not immediately return a message seeking comment but his lawyer at the time of his plea, Steven Shapiro, tells PEOPLE that Keith is seeking additional time to appeal, signaling that “he’s distressed about some aspect of [the case’s] resolution.”

Shapiro referred further questions to Keith’s current attorney and says he is barred by privilege from discussing many specific details of the case.

Keith’s children, meanwhile, continue to perform as a group. And they are opening up about their lives, the sexual abuse investigation and a new documentary about their family called The 5 Browns: Digging Through the Darkness.

Siblings Deondra, Desirae and brother Gregory (siblings Melody and Ryan did not appear) went on Megyn Kelly Today on Thursday to talk about what happened, what the documentary means and how they are working to help other survivors of sexual abuse.

The tipping point came in 2007 when the Utah-based family — who had first made headlines thanks to the siblings’ piano-playing prowess, which earned all five of them a spot at New York’s renowned Juilliard conservatory — was on tour in Japan.

There Deondra and Desirae had a candid conversation, for the first time, about the abuse they had separately survived, without knowing they were not alone.

Image zoom From left: Gregory, Deondra and Desirae Brown with Megyn Kelly on Megyn Kelly Today

As Deondra recalled on Megyn Kelly Today:

“Desirae and I were sharing a hotel room and we just were kind of talking about this internal struggle of what was happening within our family [of the siblings feeling somewhat powerless in their careers] and she point-blank asked me if there was something that I hadn’t had a chance to talk about before.

“And at first I just kind of discarded it, like many abuse survivors do where they just kind of — ‘Oh no, everything’s fine,’ and try and gloss over it. But to her credit, she kept asking, she asked several times until I finally was brave enough to say the words, ‘I’m a sexual abuse survivor at the hands of our father.’ ”

“That was one of the hardest things to say,” Deondra continued, “but now I look at it and I’m proud to say that I’ve lived through difficult things and I’m still here. We’re still performing.”

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The Brown siblings said they confronted their father and their mother, Lisa Brown, and that Keith did not deny the abuse. However, the siblings initially chose not to report what had happened, believing that they could salvage their bond as a family.

“There is a Mormon concept called repentance, where you change your heart and your life,” Kimball Thomson, a friend of the siblings, told PEOPLE reporter Christine Pelisek in 2011. “It’s a huge commitment. You try to make right the damage you caused.”

“Eventually over time, over years really, each of us came to the conclusion on our own that it was a toxic relationship that we had to, for the sake of ourselves, for our own healing, for our own little families, that we had to just set that aside and focus on ourselves,” Deondra told Megyn Kelly on Thursday.

Image zoom The Brown siblings in 2006 Theo Wargo/WireImage

Mom Lisa has chosen to stand by Keith, according to the siblings. (Lisa did not immediately return a message from PEOPLE seeking comment.)

Echoing what they said to police in 2010, Desirae told Kelly that the “catalyst” for them reporting their dad’s abuse was the revelation that he “was beginning to manage other young girls, which totally went against the things that he had been telling us.”

“We didn’t want to look back years later and regret somebody else being abused when we could have come forward,” she said.

The 5 Browns have continued to work and to record since the sexual abuse case broke open and they are preparing another tour, they said on Megyn Kelly Today.

Deondra and Desirae have also gone into advocacy, launching the Foundation for Survivors of Abuse, and they are working with politicians to seek a nationwide end to the statute of limitations on sexual abuse cases.