I think he is just making himself an easy target. It helps the mafia because they can use his planted evidence to throw him under the bus, and it looks like they outed him, and we gain their trust because hey, that person sniffed out scum, thats the way to gain trust.

if he is a jester then kudos to him for getting killed. Boo to him for taking the spotlight three days and letting the mafia hide much more easially during those days. (we did get Yukiko though despite his efforts.)