JOHNSTOWN, Pa. - A former child advocate on probation for having obscene materials, including computer images of naked boys, was charged with raping a 10-year-old boy three years ago.

Larry Scott Knipple, 46, of Stonycreek Township, was a volunteer with Cambria County's Court-Appointed Special Advocate program until he was arrested in 2005 on charges of possession of child pornography. Under a plea deal, he pleaded guilty to a lesser charge of possessing obscene materials and tampering with evidence and was sentenced in August to three years' probation.

Knipple also was fined $1,500 and ordered to perform 250 hours of community service.

The judge said the obscene materials did not show children engaged in sexual activity.

Police now accuse Knipple of sexually assaulting a boy during three months in 2004.

Police allege the boy, now 13, told investigators Knipple showed him adult and child pornography and had sex with him.

Knipple was arraigned Wednesday on charges of rape, involuntary deviate sexual intercourse, indecent assault, and unlawful contact with a minor, and released on $10,000 bond.

"I've got plenty to say, but I don't think my lawyer would want me to talk to you," Knipple said Friday. He would not divulge his attorney's name.

Knipple's preliminary hearing is scheduled for Tuesday.