A former juvenile justice worker convicted of taking sexual advantage of underage girls he was supervising at a courthouse was sentenced Tuesday to four years in prison, with a judge saying he exploited his job to prey on vulnerable victims.

Tony Simmons declined to speak at his sentencing, where he got the maximum possible punishment for his conviction in a case that had sparked demonstrations by women's advocates. He had been poised to emerge with a probation-only plea deal until a judge rescinded the agreement in November amid criticism from the district attorney and an outcry from women's rights activists.

Jurors last month found Simmons guilty of committing a criminal sexual act and sexual abuse in encounters with two girls inside the Manhattan Family Court building, but they acquitted him of raping a third girl there.

The girls — young offenders who were being held in juvenile facilities — were 15 and 16, under the age of sexual consent in New York. To state Supreme Court Justice Carol Berkman, the circumstances and Simmons' authority over them compounded his crime.

"These complainants were young. They were vulnerable. They had come from backgrounds which had failed them in some ways," she said as she sentenced Simmons, 47.

Simmons' lawyer, Gregory Watford, said he plans to appeal.

Simmons' accusers testified that he abruptly began groping them after taking them aside in the Family Court building in separate incidents between 2005 and 2008. As a counselor with the city Department of Juvenile Justice earning $37,000-a-year, Simmons was assigned to bring juvenile offenders to court and look after them there.

One girl testified that Simmons made advances that ended with her performing oral sex on him in a locker area. Another said he fondled her in a kitchen after asking her to help him unload a cooler of food.

"This is not what that kid would expect in that setting, but this is what she got," Manhattan Assistant District Attorney Evan Krutoy said Tuesday.

The third accuser said Simmons raped her in a courthouse elevator; jurors acquitted Simmons of those charges.

Watford depicted all the accusers as troubled girls who made the allegations hoping to get out of custody or get a lawsuit payout.

Simmons didn't testify at his trial, but before his plea deal collapsed, he told authorities the girls had enticed him, according to state Supreme Court Justice Cassandra Mullen. She initially approved his deal to plead guilty to rape and other charges in exchange for a promise of 10 years' probation but later voided the agreement, saying Simmons had shown a "disturbing" lack of remorse.

In the interim, Manhattan District Attorney Cyrus R. Vance Jr. had blasted the probation plan as "outrageously lenient," and National Organization for Women members and others had demonstrated outside the courthouse.

Jurors heard nothing about the guilty plea during the trial.

"Predators like Tony Simmons think these kids don't matter to society," Sonia Ossorio, the executive director of NOW's New York City chapter, said Tuesday. "But today's sentencing and this trial show that they do matter."

Simmons was suspended and then assigned to desk duty after the allegations emerged in July 2008, authorities said. He resigned in September as the Juvenile Justice Department was moving to fire him, the agency said.