"It's difficult for me to talk about," said Dave, a father who does not want his full name released in order to protect the identities of his girls.
Peoria police said three of Dave's daughters were sexually abused by their mother's boyfriend, 44-year-old Dennis Tourville.
"Devastating. It was very, very emotional," said Dave.
Tourville was arrested Oct. 31 on 20 felony charges including sexual abuse, molestation and rape of the sisters dating back to 2006, when he started dating their mother.
At the time, the girls were 16, 14 and 10.
Court paperwork says the abuse happened at Tourville's Peoria home and at Mad Hatter Mufflers and Brakes where he worked.
Police said he threatened the girls if they told anyone.
"Probably the worst thing I've ever heard as a parent. Nothing worse than that," said Dave.
Peoria police said the investigation has been under way for two years.
They said Tourville harassed the eldest daughter and put naked photos of her on Facebook. He tried to make it look like she was crazy, getting her institutionalized when she attempted to get away from him.
"We believe that he got a cell phone, registered it as the victim and were making calls and text messages to himself. Then was able to turn that information around and get her involuntarily committed," said Amanda Jacinto, the spokesperson for the Peoria Police Department.
Doctors at Recovery Innovations of Arizona let her go almost immediately.
Investigators also found that starting in 1988, multiple reports of rape against Tourville were filed in other states.
His alleged victims included a former spouse and several teenage family members.
There wasn't enough evidence to prosecute, but Peoria detectives recently located the victims.
Tourville is a convicted felon and was not allowed to possess guns. Peoria police said they found several weapons along with ammunition inside his home.
"He's a monster that's been walking in the shadows for years and nobody's known. He's gotten away with it for all these years," said Dave.
The girls' mother has not had contact with her daughters for two years.
"I think she knows a lot more than people believe," said Dave.
Police said the girls' mother refuses to cooperate, and has since married the man who stands accused of sexually abusing all of her daughters.
"I'd like to see him do prison time for the rest of his life, and not see the light of day," said Dave.
In a late statement from the eldest daughter to CBS 5 news, the victim states:
"Although I am relieved that Dennis has been arrested, I am also aware that we are far from being done with this whole ordeal. The past few years have been the most difficult time of my life. It was a nightmare I never thought I would escape. But then I realized how fortunate I am, because I fought back and won. This victory is not just for me, but for my family, and for the many other victims who suffered like I did. I am proud to finally be able to confidently say that Dennis Tourville is no longer a threat. The Peoria Police Department worked extremely hard to make this become my new reality."
Copyright 2012 CBS 5 (Meredith Corporation). All rights reserved.
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