In the months after Batman Begins, relations between the district attorney's office and the police, especially between Police Lt. Jim Gordon and newly-elected DA Harvey Dent, remained tense with corruption in the rank and file. According to a viral marketing campaign, Dent even spearheaded an initiative through his office to weed out police corruption. In response to Dent's "attacks" on the police department and the actions of the League of Shadows nine months before, Police Commissioner Gillian Loeb set up the Major Crimes Unit within the police department to counter possible terrorist attacks as well as rid the city of its organized crime. A few detectives are featured in the unit, such as Gerard Stephens, Anna Ramirez, Mike Wuertz, Murphy and McFarland. The police have also cooled their animosity towards Batman, with the official investigation jokingly placing Elvis, Abe Lincoln, and Bigfoot on their wall of suspects for the vigilante's true identity. While Stephens, Murphy and McFarland were good and honest cops, Wuertz and Ramirez were corrupt and involved in the mafia (or, in the case of Ramirez, used to be an honest cop, until she was placed in a tough situation involving her mother's life). After Loeb was killed when his drink is replaced with acid as part of a three-way attack that began the Joker's mafia-authorized reign of chaos, which also included car-bombing Gotham Court Judge Janet Surrillo and attacking a fundraiser for Dent, Gordon was appointed to replace Loeb as Commissioner by Mayor Anthony Garcia following the Joker's first capture. However, while the Joker was in the MCU jail, Wuertz and Ramirez were assigned by the mafia to kidnap Dent and his assistant DA Rachel Dawes and tie them up near gasoline barrel-activated time bombs in two separate warehouses for the psychopath. While Dawes was killed by her bomb, Batman was tricked into saving Dent, whose face was half-scarred by his bomb, and Joker escaped captivity in the MCU with the help of a cell phone-activated pre-plant bomb the he sewn into one of the henchmen who was arrested with him, Kilson, and Chinese billionaire mafia accountant Lau in tow. While Wuertz appeared to show no remorse whatsoever for his crime, Ramirez was clearly devastated by the turn of events. Dent later killed Wuertz after the coin landed on the charred side, but he spared Ramirez after the coin landed on its good side. So instead, he merely pistol-whipped her in retribution. After Dent was stopped, Batman willfully took the blame for Dent's crimes, ending the police's alliance with him and reigniting their "bat-hunt".
When Bruce Wayne returned as Batman, only one MCU detective still had faith in him before and after Bane exposed exposed Dent's crimes to the world: John Blake, who was promoted to from beat cop by the MCU after Gordon saw something of himself within the younger cop that represented an idealism that he and Batman (as Bruce Wayne) once held.