MILWAUKEE » One of two teenage girls accused of trying to kill a classmate near Milwaukee to appease the online fictional character Slender Man is being treated at a state mental hospital, the girl’s attorney said.

A judge committed the 13-year-old to the hospital in January, the (Milwaukee) Journal Sentinel reported today. The girl had been diagnosed with early onset schizophrenia during a court-ordered competency evaluation in 2014.

“She’s made substantial progress,” said the girl’s attorney, Anthony Cotton, adding that she recently began expressing remorse. “She’s starting to feel regular and normal emotions now.”

Cotton plans to again ask that the girl’s $500,000 bail be reduced to a signature bond, which would allow her to return home and continue receiving treatment while awaiting trial. The other girl is being held at a West Bend juvenile jail.

The two girls are charged with attempted first-degree intentional homicide in the May 2014 attack on Payton Leutner. Investigators say the girls lured Payton to a park in Waukesha, about 20 miles west of Milwaukee, where they stabbed her 19 times in an attempted sacrifice to a fictitious horror character called Slender Man. Payton was left for dead but managed to crawl from a wooded area where she was discovered by a bicyclist.

After several surgeries, Payton has returned to school. She is now in eighth grade.

Defense attorneys have tried to have the case transferred to juvenile court. They are appealing a decision by Waukesha County Circuit Judge Michael Bohren last August to keep the girls’ case in adult court, where convictions could send them to prison for up to 45 years. As juveniles, they could be incarcerated for up to three years and then supervised until age 18.

Final defense briefs are due Monday, and the Wisconsin Court of Appeals could begin reviewing the case this month. The Associated Press hasn’t identified the girls because the case could return to juvenile court, where proceedings are closed.

An HBO documentary about the case, “Beware the Slenderman,” premiered Friday night at the South by Southwest festival in Austin, Texas. The 114-minute film examines both the Wisconsin stabbing and how children can become easily drawn into beliefs spread through the Internet.

Stephen Lyons, a Madison lobbyist who has been a spokesman for the Leutner family, said Payton has recovered from her physical injuries but still faces an emotional recovery. Supporters have contributed about $200,000 for her ongoing care, and Lyons said everyone at her middle school has been supportive.

“But part of the healing is she wants to get beyond being the victim in the Slender Man case,” he said. “Now it’s on to the next step.”