Foley, a six-term Republican member of the House of Representatives, resigned abruptly last week as his e-mails and instant message transcripts surfaced. The chats discussed sexual acts and possible meetings between Foley and the pages.
With the FBI investigating Foley's behavior, defense attorney David Roth said Tuesday that the congressman never had sex or attempted sexual contact with a minor. Foley, who is being treated for alcohol abuse, was drinking when he had the explicit conversations, Roth said.
"Any suggestion that Mark Foley is a pedophile is false," Roth said at a news conference in Florida.
If Foley never had sex with a congressional page, then his case is in uncertain legal territory, said Ken Lanning, a retired FBI agent who served as one of the agency's leading experts on child exploitation.
"There are going to be some issues here in the gray area," Lanning said. "You may find this behavior repulsive, offensive or immoral. Whether it's a violation of law will be based on a precise reading of the law."
Congressional leaders, who called for an FBI investigation as Foley resigned late last week, now have turned to finger-pointing over who knew what about Foley's behavior, when they knew it and whether anything was done to protect the teenagers who serve as House pages.
One federal law enforcement official said the FBI reviewed some Foley-related e-mail in July but concluded that no federal law had been violated. The official, who spoke on condition of anonymity because the case is active, said agents are reviewing new evidence, including the instant message transcripts, to see if a law was broken.
FBI spokesman Richard Kolko said the agency "is continuing its assessment in the Congressman Foley matter."
In Florida, Roth said no law enforcement officials had contacted him. Foley has not been subpoenaed but voluntarily agreed not to delete any e-mails or instant messages from his computers, the lawyer said.
Some Democrats have claimed Foley might have violated the same federal law used to prosecute Internet sex predators, but experts said it is not that simple.
On the surface, the chat transcripts released by ABC News look much like any of the explicit conversations the FBI has used as evidence in its many Internet sex stings. In those cases, however, the sexually charged talk leads to an arrest when adults arrive for real-life sexual encounters.
Graphic talk alone is rarely enough, said Joseph Dooley, a former agent who helped set up New England's first FBI unit targeting Internet predators. Many adults engage in explicit chats with undercover agents, but never show up for the scheduled meetings, he said.
"We never charged anyone unless they actually traveled to have sex," Dooley said.
Investigators could consider federal obscenity laws, experts said, but the law prohibiting disseminating obscene material to children applies only to those under 16.
Benjamin Vernia, a former federal prosecutor specializing in such cases, compared Foley's online conversations with pages to "grooming" — a law enforcement term for the way sexual predators bring along their underage victims.
Grooming is a red flag for authorities, Vernia said, but it's rarely enough to bring charges.
The question for federal investigators is whether Foley's online chats ever led to real-life encounters. One chat transcript suggests Foley and a page had met in California, but the chat does not indicate what took place.
Even if a sexual encounter had occurred, however, that would not necessarily be enough to lead to charges, because it depends on how old the pages were at the time and what the age of consent was in that state.
If a state crime has been broken and authorities can show Foley used the Internet to facilitate it, that could trigger federal jurisdiction, experts said.