A former staffer at Wordsworth, a residential treatment center for troubled children and teens, has been charged with sexually assaulting three girls in the program, luring them to the basement of the now-shuttered facility for sex and forcing them to take naked photographs of themselves with his iPhone.

Isaac Outten, 37, repeatedly had sex with three girls, ages 15 to 17, while they were living at the West Philadelphia center last year, police said. He lured the 15-year-old into performing oral sex and having intercourse in exchange for a promise of money for diapers and milk for her 1-year-old child, they said.

He promised another girl, 17, that he would help her with a criminal case in exchange for sex and naked selfies, according to police. And he led the third girl, also 17, to the basement for sex after a counselor left her alone with him, police said, and warned her not to tell anyone because that would get him into trouble.

Outten, who was fired after the allegations came to light late last year, faces charges of institutional sexual assault, involuntary deviate sexual intercourse, corruption of minors, endangering the welfare of children, and other crimes. He was being held at the Curran-Fromhold Correctional Facility on $200,000 bail in each of the three cases.

His arrest Tuesday was the latest setback for Wordsworth, which was ordered to close in October after a 17-year-old boy died in a fight with staffers who had come to his room in search of a stolen iPod. The staffers flipped over the boy's bed and tossed the furniture around, and he grew agitated, according to a report prepared by state officials.

As staffers attempted to restrain him, one held the boy's legs as another punched him repeatedly in the ribs, the report said. The boy began gasping for breath, at one point yelling, "Get off me. I can't breathe," according to the report. Then, it said, the room fell silent.

No one has been charged in connection with the death, which is being investigated by Philadelphia police and the state Department of Human Services, which regulates Wordsworth.

Shortly after the boy's death on Oct. 13, DHS revoked Wordsworth's license and ordered it to close, citing "gross incompetence, negligence and misconduct in operating the facility." Wordsworth officials have appealed the decision.

Among the violations cited by state officials in justifying closure were the three girls' allegations that Outten had sexually assaulted them.

DHS had ordered Wordsworth to appoint a security manager to ensure the safety of children who live there, strengthen staff training, and make clear that abuse would not be tolerated. In an inspection of the facility four days after the boy's death, state officials reported that Wordsworth had made "inadequate progress" in carrying out those actions.

A spokesman for Wordsworth said Outten was immediately suspended when the girls reported the assaults and was fired soon after. She declined further comment, citing pending litigation.

Outten's lawyer did not return a phone call seeking comment.

In addition to its residential treatment facility, Wordsworth offers educational programs, mental health services, and foster care, and does case-management work for the city Department of Health and Human Services. Those programs are unaffected by the closure order.

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Staff writer Chris Palmer contributed to this article.