Prison time appeared to be looming for two San Francisco Chronicle reporters who refused to divulge who leaked them secret grand jury documents from the BALCO steroids investigation. Then the source finally stepped forward. But it wasn't until the FBI got a tip more than two years after the leak that the case began unraveling. The tip led investigators to attorney Troy Ellerman, who agreed Wednesday to a plea deal that lets the reporters off the legal hook. In court papers filed in U.S. District Court, Ellerman said he allowed the Chronicle's Lance Williams and Mark Fainaru-Wada to view transcripts of the grand jury testimony of baseball stars Barry Bonds, Jason Giambi, Gary Sheffield and sprinter Tim Montgomery.