Prentice, who is supervising the criminal investigation, said the Sheriff's Office had fielded a number of allegations over the years that Chad residents had been assaulted, either by staff or by one another.

"There are reports all the time," he said. "There's a lot of runaways, stories [from children] that 'We're being abused out there.' We've had some broken arms, some separated shoulders."

Prentice said victims would stop cooperating with investigators, apparently because they feared retaliation from staff or other youths. No charges have been lodged in any incident, he said.

"They're mostly street kids," he said. "They think they're better off to keep their mouth shut."

Investigators from Philadelphia recently spoke with about 20 city children at Chad and heard allegations that raised "serious concerns," said Robert Listenbee, chief of the juvenile unit at the public defender's office.

"The general feeling is that there are a lot of restraints, daily, weekly and monthly," he said.

Before Leach died, Listenbee said, a child from Philadelphia sustained a broken arm; since the death, another Philadelphia youth has suffered facial injuries during a restraint, he said.

"We're concerned about how frequently they use restraints, the types they use, and the quality of training they have received," he said.

A troubled young man

Outside the Leach family rowhouse in a battered part of Southwest Philadelphia, the walls are adorned with posters with his photo and words of farewell for "Manny," as he was known to friends and relatives.

His mother, Paulette Dolby, cried when asked about her son. She referred reporters to a lawyer, Edith Pearce, who is investigating the death for a possible lawsuit.

Pearce described Leach as an ordinary teenager who loved basketball and video games and doted on his younger sister. He carried a grade point average of 2.7 at Daniel Boone disciplinary school.

"My career goal is to be a lawyer," he wrote recently, in words quoted in his funeral program. "I like helping people, so I plan to be an affordable lawyer, and in that case I will have to go to college."

His father, Omega Leach Jr., 50, has been arrested nine times in two decades and has served time for burglary and drug dealing.

The younger Leach also had a long history of problems. One psychological report called Leach a "deeply troubled and difficult young man."

According to official records, police arrested Leach at age 14 after he allegedly cursed and threatened students and teachers at his school, Tilden Middle. He told one teacher he would "shoot him full of shells," police said.

"His mother is very afraid of him and his behavior," police wrote. The teenager "is out of control."

The city tried to straighten him out. In January 2005, just before Leach turned 15, he was sent to a private facility in Virginia.

By the time he was 16, Leach was back in Southwest Philadelphia. In December, police arrested him for racing through his neighborhood in a stolen Nissan.