Zach Tomaselli, 23, alleges Fine invited him to a basketball game in Pittsburgh in January 2002 and then sexually assaulted him in a hotel room.
He made the accusation after two former Syracuse ball boys said Fine had abused them.
Lawyer Jeff Anderson told a news conference Fine might face criminal charges in Pennsylvania, USA Today reported. Fine cannot be charged in New York State because the statute of limitations has expired.
"We take this action today because Zach and we really believe it's important that the survivors know they can come forward," Anderson said. "In Zach's case, he has chosen to come forward publicly. They can also come forward privately."
In New York, Onondaga County District Attorney William Fitzpatrick said Wednesday he is turning over potentially exculpatory evidence about the Tomaselli charges to Fine's lawyers.
Tomaselli read a statement Thursday about charges that he abused a boy in Lewiston, Maine.
"I was sexually abused by Bernie Fine after he invited me to a Syracuse game," Tomaselli said. "At the time I wasn't even able to understand the process as abuse. But now I know what harm he has done to me and others. I know I have done harm to a child … and for that I am deeply sorry and need to be truthful."