"I believe that his disappearance is almost certainly related to this Penn State debacle," Wecht said.
Ray Gricar disappeared in 2005 and was declared dead earlier this year.
"You've got his car being found, locked with cellphones inside. The computers found and the hard drive is found there in the river. The body is never found," Wecht said. "Looks to me like it was staged."
Gricar decided not to prosecute Jerry Sandusky in 1998, despite having enough evidence to do so. Wecht said guilt could have drove Gricar to suicide.
"It might have stopped this. I might have kept other children from being victimized. So you do have a plausible suicidal scenario," Wecht said.
However Wecht said the murder motive is strong since more allegations of child abuse against Sandusky increased his chances of going to prison.
"He may have maybe went back to somebody and said, 'I let it go back in '98 but I can't let it go any longer,'" Wecht said.