Updated 1/26/11 10:48 p.m.

CHICAGO (CBS) — A family is suing Cook County authorities, after a convicted sex offender sexually assaulted their teenage daughter while out of jail despite having violated probation.

The lawsuit was filed in U.S. District Court on behalf of the girl’s mother, against Cook County Chief Probation Officer Jesus Reyes, and the sexual assault suspect, Acurie Collier.

The girl’s mother called 911, then entered the girl’s bedroom and was able to restrain Collier by the limbs before he was arrested, the lawsuit said.

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Collier, 36, allegedly sexually assaulted the 13-year-old girl on July 30, 2010, after getting her home address during online chats were he posed as a young boy, according to the lawsuit. The Stickney man forced his way into their home on the city’s South Side, authorities said.

The Illinois Policy Institute discovered in December that at the time of the attack, Collier had been on probation for a charge of aggravated criminal sexual assault. He was being supervised by the probation department’s Adult Sexual Offender Program, authorities said.

An investigation determined that Collier violated his probation at least 17 and possibly as many as 40 times, the lawsuit said. Yet the probation officer, who visited the home multiple times, did nothing, the lawsuit said.

“This man was not at home and wasn’t where he was supposed to be,” said family attorney Tim Cavanagh. “The probation officer never arrested him or notified the state’s attorney or police to have him arrested for probation violations.”

The lawsuit accused Reyes and the probation department of being negligent and breaching their duty. The lawsuit also accused Collier of battery, false imprisonment, and intentional infliction of emotional distress.

The lawsuit seeks unspecified damages.

Newsradio 780 tried to reach the probation department chief for reaction, but the office of the chief judge of Cook County says neither judges nor their employees may comment on any pending court cases.

The chief judge’s office says the Cook County state’s attorney will represent the probation department chief in the federal lawsuit.

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