What information does Nortier reveal from the safe?

The safe contained the minutes from a Bonapartist meeting in February of 1815. This was when Franz's father was assassinated. Nortier reads the minutes, which reveal that Franz's father was taken to a Bonapartist meeting, where he maintained his loyalty to the monarch, Louis XVIII. When he was returned from the meeting he insulted the president of the meeting. The two then engaged in a duel where the Bonapartist, who remains unnamed in the minutes, wins. The body of Franz's father is thrown into the river. Franz is shocked to finally learn the details of his father's death. He is further shocked when Noirtier tells him that it was he who killed his father. Noirtier was president of the Bonapartist meeting.