Poor Fusco was shot, and now is the lone member of "Internal Investigations" for Reese. Eventually, I can see that he will need to take down the whole HR (bad cop) apparatus.
It HAS been shown that Reese is a very focused guy. He told the kid in one episode that they got the person who killed his brother, let it go at that. the kid wanted to go after that guy's boss, and Reese told him NO! If you go after his boss, and then his boss, eventually, you will jut get yourself killed, and basically for nothing. It'll just be more killing, and revenge killing. Now THAT'S focused!