An Ohio couple charged with imprisoning three of their adopted children - two girls and a boy - for 22 hours a day and abusing them have pleaded not guilty, in a case that began after the girls managed to escape the 'house of horrors' and crashed the family van. The 58-year-old adopted father is charged with sexually abusing the two girls, who were 11 and 13 at the time of the alleged ordeal. He and his 64-year-old wife are both charged with kidnapping, felonious assault and endangering children in Ashtabula County, about 50 miles east of Cleveland. The suspects are not being named, in order to protect the identities of the victims. Abuse: Between September 2011 and September 2013, two juvenile girls and a mentally handicapped adult male were locked in their bedrooms 'virtually all day every day' and abused, prosecutors say. Their adoptive parents - who are not being identified - plead not guilty Wednesday to a variety of charges . County Prosecutor Nicholas Iarocci said the couple also abused and neglected their adopted son, now 21, who is mentally disabled. Iarocci said Wednesday that the couple 'repeatedly and harshly' beat the girls and older son with a paddle that police found to be stained with blood. The three victims were given little to eat and were malnourished, Iarocci said. He called living conditions inside the home 'deplorable.' The victims were typically allowed out of their rooms for two hours a day for school lessons, to eat and to use the bathroom, Iarocci said. They were not allowed to socialize with other children in recent years, he said. Iarocci could not explain why a younger adopted son, now 13, was not abused. Indictments allege the abuse occurred over a two-year period starting in September 2011. The investigation began after the two girls managed to pick the lock on their shared bedroom - the windows of which were boarded up - and escape in August 2013, speeding away in the van before getting into an accident, Iarocci said. After telling responding officers that they feared going home, the girls reluctantly revealed their squalid living conditions. The sisters did not mention the alleged abuse until after they were charged in the accident, and then they told their probation officer, according to the prosecutor. 'To be honest with you, as these children told me the story, it was hard to hold back some of the tears,' Iarocci told Fox 8 Cleveland. House of horrors: Two girls and an adopted boy were locked up in bedrooms in the couple's home, pictured, and the abuse only emerged after the girls escaped and stole the parents' car - but later crashed . Buckets and a metal container were left in the bedrooms for them to use as a bathroom when they were locked away, he said. The three children and the man were  removed from the home and placed in foster care a month after the crash. The couple adopted six children about 11 years ago but the abuse began only after two older boys left the family home after turning 18, Iarocci said. We can't explain why these people did what they did and when it started,' Larocci said. The abuse inflicted psychological damage on the girls, but they and their older adopted brother have thrived in foster care, Iarocci said. 'They're almost different children,' he said, adding that the girls are being adopted by another family. An attorney for the husband declined to comment on Wednesday. The wife is expected to be assigned an attorney in the next few days. Each are being held on $50,000 bail. Horrific: County prosecutor Nicholas Iarocci, pictured, said he cried when the girls detailed their abuse and he believes the system failed when they put the children in the couple's home . The children had been previously placed in the couple's home by Ashtabula County Children Services following background checks - but Iarocci said he didn't know how it had happened. 'I can't explain how these children ultimately were adopted by them - how they were originally fostered by these folks,' he told Fox 8. 'I think it's a failure of our system. Our system was broke. For any child to be placed in the custody or care of [the accused] was a terrible mistake.'
Father, 58, of Ashtabula County, pleaded not guilty to sexual abuse . He and his wife, 64, charged with kidnap, assault and child endangerment . Abuse emerged after the two girls escaped their locked room, stole their parents' car and crashed it . They told police they were 'locked up for 22 hours a day, made to use a bucket for the bathroom and sexually assaulted'
The couple 'also abused an adopted son, who is mentally challenged'