Detective Gerard Stephens was one of Gordon's officers in the Major Crimes Unit and a former supporter of the Batman.
After the assassination of Judge Surillo and Commissioner Loeb, Stephens privately spoke with Gordon at the GCPD, telling him that the threat posed by the Joker would prevent the people of Gotham from stepping up to to persecute the Mob members that Gordon and Harvey Dent had arrested.
Stephens attended Commissioner Loeb's service, during which Gordon was shot by the Joker and his henchmen (whom were disguised as the honor guard) protecting the Mayor of Gotham and presumbed dead. Afterwards, Stephen and Ramirez gently informed Barbara Gordon of Jim's "death". After Gordon's death, Stephens took over MCU and attempted to maintain contact with the Batman, but gave up when Batman didn't respond to the Bat-Signal. Stephens was present when the Joker was successfully apprehended by Batman and Gordon (who was revealed to have survived), among those whom applauded Gordon's promotion to Police Commsioner, and when Batman interrogated the Joker for Harvey Dent's location after the latter was abducted by the Mob. Stephen kept guard over the Joker as both Gordon and Batman attempted to save Harvey Dent and Rachel Dawes, but was provoked into attaking the Joker after being taunted by the latter of the former's friends the latter killed while implying that they died as cowards. Stephens lost, and then the Joker picked up a shard of the two-way mirror that Batman smashed the Joker into earlier during the interrogation, holding the shard to Stephen's neck and holding him hostage in front of the other MCU cops. At the risk of his own life, Stephens told the cops to shoot the Joker, blaming himself for letting the Joker loose. Demanding a phone call, the Joker calmed the panicking crowd before he detonated a nearby bomb placed inside one of his imprisoned henchmen.
Gerard was released safely by the Joker after the explosion but was rendered unconscious. Gerard would have his neck bandaged for the Joker's glass inflicted cut. Along with Commissioner James Gordon, he watched the news covering the Joker's threat of blowing up hospitals. Gerard also stood by Gordon as he smashed the Batsignal with an axe.
It is unknown what happened to him after the events of the Dark Knight.
In contrast to cops like Wuertz and (technically) Anna Ramirez, Stephens proves himself to be an honest man, though not above engaging in police brutality against cop-killers like the Joker. He is able to put his duty before his life when he is taken hostage by the Joker and tells the cops that it was his fault and told them to shoot the Joker despite his life being at risk. He is also very loyal to Gordon and was supportive of Batman until he was blamed for murders committed by Two-Face.