Peter Grogan was the Police Commissioner of Gotham City, operating during the early days of Batman. Although an honest cop, he distrusted the vigilante and his methods, believing him to be a loose cannon and quite brutal. However, during the Children of Arkham's attacks and Harvey Dent's reign as Mayor, he began to respect the vigilante and worked with him to stop them.
It is unknown how long Grogan has been Commissioner for before the beginning of the series, but it could be assumed that he took over the role after his predecessor stepped down or was forced to resign. During his time in the role, the vigilante Batman was operating in Gotham City, although it's unknown if he began before or during Grogan's appointment. Unlike some cops in the GCPD, like Lt. Gordon, he believed the vigilante was interfering with Police business and sabotaging evidence.
Gordon says that he had a family, though it is not known who his wife and children were. Shortly before the series, he placed the Lieutenant in charge of the Major Crimes unit, to cope with rising numbers of crimes and the Batman.
It is unknown whether Gordon was able to talk Grogan into working with Batman during the Children of Arkham's attacks on the city, but he was able to call an alliance between his taskforce and the vigilante. Grogan could be heard talking to Gordon about the service's Wayne Tech being compromised by the Children of Arkham and was talked into getting rid of the technology, preventing their messages from being heard by the group but preventing officers from communicating.
Following an anonymous tip from Batman, asking officers to come to Gotham Heights, Grogan went with his officers to investigate. Upon arriving, he took over the investigation from Gordon, believing Batman to have interfered with the investigation and tampered with evidence. Grogan and his officers were able to gather the evidence collected by Batman and Gordon, along with the knowledge of Lady Arkham's identity and the location of the Children of Arkham's chemicals.
Later, Dent and his enforcers arrived at the GCPD and threatened Grogan to hand over the knowledge they had gathered. Grogan complied, possibly having been blackmailed into surrendering it, which later led to Dent destroying the warehouse where the chemical was stored, along with the city block it resided in and several of his enforcers. If Batman chooses to confront Dent, he will later suggest that Gordon tries to convince Grogan to help take down Dent.
Depending on who Batman chose to stop in the previous episode, two possibilities will happen to Grogan.
If Batman chose to stop Penguin and the Children from hacking his Bat-Tech, Grogan and his officers would clash with Dent on occasions. After he refused to comply with him, calling him "a murderer and terrorist", the mayor sends his enforcers to capture and kill Grogan, along with many of the GCPD's officers.
As Grogan is dragged into the precinct's lobby to be executed, he was saved by Batman, who knocked out his attacker and helped him up. Grogan and his officers helped the vigilante battle the enforcers and retake the precinct. However, after Batman is caught off guard by one of Dent's men, Grogan tried to tackle the gun out of their hands, only to be shot it the torso as he did so. Depending on whether Batman can react in time, he will either be able to subdue the enforcer, preventing him from escaping, or let him run, only for them to be shot by Gordon. As Grogan died, he encouraged the vigilante to stop Dent and prevent further bloodshed from his enforcers.
If Batman chose to stop Harvey Dent and his enforcers, the Children of Arkham attack Café Trisle in the hopes the draw the vigilante out. After Grogan tried to interfere, he was captured by the group and held as one of the hostages. When Batman arrived to stop the Children of Arkham, Grogan was one of the hostages he chose to free first.
However, as Batman approached a device set up to incapacitate his armor, Grogan tried to warn him but was too late. With the mercenaries setting up to execute Batman, he tackled one of them, preventing them from shooting Batman. Eventually, the mercenary was able to gain the upper hand and shoot Grogan. Though Batman tried to intervene, his grappling gun malfunctioned, prevent him from saving the commissioner. As Grogan died, he encouraged the vigilante to stop Lady Arkham and the group, hoping he could save the city.
Batman, as Bruce Wayne, would later be able to assist in the capture of either Penguin or Dent, who was responsible for Grogan's death. Following his death, Gordon was given the position of acting Commissioner, though was unsure he could ever be able to live up to expectations set up by the late commissioner.
Grogan was an honest cop, who believed that his force should be capable to take down the criminals of the city. This was one of the reasons why he did not operate with the Batman, but trusted his officers like James Gordon. Grogan is said to have had a family, whom he cared for deeply. He was also willing to put his life before others to try and protect both his officers and the people of Gotham, including Batman.
Lt. James GordonEdit
Though they seemed to disagree on a number of issues, it is believed that Grogan had utmost respect for Gordon and would listen to him. However, when he saw the Lieutenant had overstepped his boundaries, he would, at times, step in and take over his investigations. Grogan would also trust Gordon with the special crimes taskforce, which was put in charge of taking down organized crime, including Carmine Falcone and his organization.
It is unclear what Dent and Grogan's relationship was before the District Attorney's appointment as mayor. However, after he ordered the destruction of an entire city block to destroy a cache of the Children of Arkham's drug, Grogan would see the mayor as nothing more than a terrorist and a threat to the city. These comments would later lead to his death, if Batman chooses to stop the Children of Arkham from compromising his tech.
Grogan was distrustful of Batman and believed the vigilante to be interfering with police business. This distrust could also be put to Batman's brutal methods of dealing with criminals, if he chooses to perform actions such as brutalize Falcone. However, during either Dent's dictatorship of the city or the Children of Arkham's attacks, he would come to believe the vigilante would be the only person capable of stopping them. As Grogan died, he encouraged the vigilante to do so, meaning he might have come to respect him and what he stood for.
- Unlike his comic book counterpart, this iteration of Grogan was not corrupt and had no ties to organized crime.