A juvenile justice worker accused of molesting teenage girls inside a courthouse was set to get a no-jail sentence Monday until a judge threw out his plea deal, which had sparked criticism from the district attorney and outrage among women's advocates.

Charged with having sexual encounters with three underage girls in his custody at the Manhattan Family Court building, Tony Simmons became a flashpoint for debate and protest after state Supreme Court Justice Cassandra Mullen pledged in September to sentence him to 10 years' probation. He had pleaded guilty to rape and other charges.

Mullen said Monday she couldn't keep the promise because Simmons showed a "disturbing" lack of remorse and responsibility during presentencing interviews.

Despite his guilty plea, he told probation interviewers the girls had enticed him, claiming one thanked him after he allegedly raped her, the judge said. The girls were 15 and 16, below the age of consent in New York.

"There is nothing more fundamental to our system of justice than that a court accept a guilty plea only from those who understand their guilt and unequivocally admit it," Mullen said. "(Simmons) does not admit his guilt and, more alarming, has no understanding that his conduct was wrong and, perhaps most outrageously, blames the victims."

The judge said she would offer Simmons a three-year prison term instead or let him withdraw his plea. After Simmons declined both options, Mullen voided his plea.

That puts his case back on track for trial and negates his prior admission of guilt. It can't be used against him at a potential trial.

Simmons' lawyer worried that the presentencing interviews would provide fodder for prosecutors.

"Now they'll be able to try to disprove everything that he'll be putting forward" in his defense, lawyer Gregory Watford said.

Simmons, 47, is free on bond while the case plays out. The top charges against him are punishable by up to four years in prison, but his potential penalty is hard to calculate because of the complexities of sentencing laws.

As a roughly $37,000-a-year counselor with the city Department of Juvenile Justice, Simmons was tasked with picking up young offenders at facilities where they're held, bringing them to court and supervising them there, prosecutors said. Their cases generally are handled in Family Court.

He had sexual encounters with the girls in out-of-the-way spots in the Family Court building in 2005 and 2008, prosecutors said.

When Mullen promised Simmons probation this fall, Manhattan District Attorney Cyrus R. Vance Jr. blasted the proposed punishment as "outrageously lenient," though a transcript later showed an assistant prosecutor had not objected to it, at least on the record. Vance's office had no immediate comment on Monday's developments.

The planned no-prison deal spurred a critical editorial in the Daily News and prompted National Organization for Women members and others to demonstrate outside the courthouse last week.

"This is a very troubling case because it involves teenage girls, and it involves someone who was an employee of the government. He was in a position of power," Sonia Ossorio, the executive director of NOW's New York City branch, said in an interview earlier this month.

Simmons was suspended and then assigned to desk duty after the allegations emerged in July 2008, authorities said. His current status wasn't immediately clear Monday.