Maimonides' Book of Judges contains the following sections: laws of the Sanhedrin and the punishments they enforce, laws of witnesses, laws of rebels, laws of mourning, and laws of kings and their wars.
Why are the laws of mourning included here with various procedural-judicial laws? I'd have thought to see them in the Book of Knowledge near the laws of repentance and behavior, or perhaps in the Book of Love with the common ritual laws which aren't calendar related such as circumcision and prayer.