Gotham Central Book 3 - On the Freak Beat (2011)

A brutal gang war rages in Gotham City. After a tragic mistake, the police feels that they can no longer trust Batman, so the Commissioner makes a fateful decision -- the Dark Knight is now a wanted man, and the famous Bat-Signal is removed from the roof of headquarters.
Plus, Detective Renee Montoya investigates the disappearance of important evidence amid a gang war and travels to Keystone City in an attempt to unveil the truth about Officer Kelly's strange mutation.
Collecting GOTHAM CENTRAL #23-31.