Prosecutors investigating allegations of child molestation against former Syracuse assistant basketball coach Bernie Fine face obstacles that include finding corroborating proof, statutes of limitations on old accusations, and the credibility of the men who accuse him of sex abuse.

The 65-year-old Fine, who had been coach Jim Boeheim's top assistant since 1976, has adamantly denied wrongdoing. He was fired when three men made public accusations and ESPN played a 2002 recording of a phone call in which a woman ESPN identified as Laurie Fine, the coach's wife, tells accuser Bobby Davis she knew "everything that went on."

But state charges against Fine are out, for the time being. Davis is now 39 and his stepbrother Mike Lang, another former ball boy who also told ESPN that Fine molested him, is 45; both men say they were first abused as boys in the 1980s. Any crimes against them happened so long ago that the statute of limitations has expired. Davis went to police in 2002 but even then, it was already too late to bring any charges in New York.

That leaves a federal prosecution.

The U.S. Secret Service is running that investigation and it hinges on the claims of a third man, Zach Tomaselli of Lewiston, Maine. He has told authorities that Fine molested him in 2002 in a Pittsburgh hotel room on a team trip from Syracuse. He said Fine touched him "multiple" times in that one incident.

The federal statute of limitations that went into effect in 2002 allows prosecution until the victim reaches age 25; Tomaselli is 23 so there is still a window to bring charges.

Lee Kindlon, a criminal defense attorney who practices in state and federal courts, said even though that federal case could proceed, prosecutors will still have to jump other hurdles including a lack of physical proof for something that allegedly happened nine years ago, and Tomaselli's credibility.

Tomaselli faces his own sex abuse charges in Maine and told The Associated Press on Monday he would plead guilty to abusing a 13-year-old boy. He also accused his father of sexually abusing him but a New York State Police investigation that ended in September did not result in charges. The father, Fred Tomaselli, has said he thinks his son is lying about Fine.

"But these allegations are serious and I think the feds are doing the right thing and looking for proof to back up the accusations," Kindlon said.

Investigators searched Fine's home, office and school locker, looking for pornography that could be used "to sexually arouse or groom young males" to have sex. They took computers, cameras, disks and records, among other things. They're also looking for any records that would detail Fine's contact with boys.

Fine was fired on Nov. 27 after Tomaselli came forward and the tape was released.

Lawyers said the tape would probably be classified as hearsay and couldn't be used at trial. And Laurie Fine also generally couldn't be compelled to testify against her husband about anything he told her, though that marital privilege does not extend to what she personally saw.

Paul DerOhannesian, a defense lawyer and former Albany County prosecutor, said prosecutors still have some tools they can use: They can bring information and witnesses before a grand jury, which can result in perjury charges when witnesses are suspected of lying. That happened in the Penn State case involving a former assistant football coach and administrators, he said.

Syracuse University had its law firm investigate Davis' claims in 2005 and said the probe found no evidence to back up the accusations. The school was under no obligation to involve or inform law enforcement.

With the Fine scandal making headlines, authorities say other accusers may come forward but cases generally require more than an individual's statement. Without direct evidence, they could build a case around circumstantial evidence or indications of a cover-up, among other things, DerOhannesian said.

"Prosecutors will want to corroborate to the extent possible. That's really what an investigation is about, to corroborate an allegation," he said.

And federal prosecutors in northern New York, who claim a 98 percent conviction rate, acknowledge they usually bring cases they can win.