In the days before he was arrested in the parking lot of a hip hop club on charges that he tried to buy cocaine, Judge Jack T. Camp was in his courtroom presiding over the trial of a trucker accused of trying to sell marijuana.

On Sept. 28, three days before his arrest, Camp denied a motion for a directed verdict brought by the trucker’s lawyers. That same day, the FBI reported, the 66-year-old senior federal judge talked with an exotic dancer whom he’d paid for sex about buying cocaine and a prescription painkiller similar to OxyContin. The dancer was an FBI informant.