The Judge Advocate General's Report was a report written by an officer in the Judge Advocate General.
One of these reports, from stardate 36764, was on the subject of mutiny aboard the USS Pegasus. The writer concluded the report by stating, "Based on testimony from Captain Pressman and other surviving officers, the Judge Advocate believes there is sufficient evidence to conclude that certain members of the crew did mutiny against the captain just prior to the destruction of the Pegasus."
This report was later classified by Starfleet Intelligence. In 2370, before he could access the report, Captain Jean-Luc Picard of the USS Enterprise-D had to pull in favors at Starfleet. (TNG: "The Pegasus")