A former confidant of Representative Matt Gaetz, Republican of Florida, admitted in court papers on Friday to an array of federal crimes — including sex trafficking of a minor — and agreed to cooperate with the Justice Department’s investigations, handing prosecutors a potential key witness as they decide whether to charge Mr. Gaetz. Joel Greenberg, who was a tax collector in the Orlando area until he was indicted last year, did not implicate Mr. Gaetz by name in papers filed by prosecutors in Federal District Court in Orlando. But Mr. Greenberg admitted that he and unidentified others had paid a...
