Renee Montoya was an officer and later a detective of the Gotham Police Department.
A young cop fresh to the force, Montoya was not sure what to think of the Batman, or costumed folk in general. Wisecracking yet strict, she was ordered to guard Harvey Dent in the hospital when he was poisoned. Though she did not catch the culprit, Pamela Isley, she would have several future encounters with her.
One of her first major assignments was a drug bust that ended up going disastrously wrong. She was originally supposed to meet Bullock, along with her partner, Officer Wilkes, at a warehouse and enter it together when a known drug lord's men were inside. Instead, they arrived to find Bullock's car empty and the building on fire. As a pair of thugs burst from the building, Montoya told Wilkes to pursue them, and entered the warehouse alone. There, she confronted a squad of thugs by herself. One of the thugs disarmed her, and the rest attacked. Montoya stood her ground and actually fought them off for a while, but was close to being killed when Batman intervened and helped her defeat them. As she escaped the building, Batman was apparently knocked out or killed.
In the aftermath of the fiasco, Montoya, along with Wilkes and Bullock, was suspended from duty. However, she continued to puzzle over a conversation between the thugs she had half-heard as she entered. While passing the docks in a commuter train, she realized they had been referring to a warehouse there. She entered the warehouse alone, and saw Batman being held prisoner. Even as he escaped his bonds, she took control of a crane and aided him. When the drug lord, who was present in person, tried to flee, Montoya personally nabbed him by catching him in the crane's jaws. She and the others were reinstated, with her making sure to share the credit with Wilkes and Bullock.
For her efforts, she was promoted to sergeant, and later transferred to Special Crimes, where she was promoted to detective. She partnered up with Bullock, and though they were quite different, they got along well.
When the men of Gotham City—and with that, 80 percent of the GPD—suddenly disappeared, Montoya found herself one of the highest-ranking members of the force left. She disliked the acting commissioner, Caroline Greenway, and her no-Bat policy, instead swearing loyalty to the vanished Gordon. She initially got support from acting mayor Elizabeth Styles, though that quickly diminished. Montoya kept loyal to the police, and when the men reappeared, her squad managed to arrest Catwoman.
Batgirl, however, managed to spring Catwoman, along with Harley Quinn and Poison Ivy, from Gotham Tombs penitentiary. The sudden turn of the Caped Crusader's helper hit her hard, and she started to lose confidence in masked vigilantism. She also lost faith in the police, however. Ever since his return, Commissioner Gordon was much more a hard-liner, and allowed his men to go much further. An explosion caused by an over-the-top trap set for Catwoman knocked out Montoya, spraining her left arm. She quickly returned to work, and partnered with Gordon to follow several leads in the search for the now outlawed Batgirl. The leads turned out to be decoys, and she returned to the Department's headquarters. There, she caught the real Batgirl, after she had just pushed the Commissioner in the Bat-signal. She was shocked to learn that the aggressive Gordon was not Gordon at all, but a duplicant robot. Together with Batgirl, she puzzled together the last clues that lead to the culprit: Dora Smithy, Gordon's assistant, was Mr. Freeze's sister-in-law, and she vowed revenge for the apparent murder of her sister by eliminating all men. Montoya and Batgirl took a squad car to arrest Dora at the Gotham Ice Cream Industries. While Batgirl fought the crazed menace, Montoya found herself locked inside a frozen squad car.
Some time later, Montoya either left the force, was reassigned, or was promoted. Harvey Bullock found a new partner in Sonia Alcana, a cop not that different from her, save for the fact she was one of the three women posing as the vigilante Batwoman and left Gotham upon her identity being discovered.
According to Bruce Timm, it was clear for the start that they needed a strong female policewoman as an audience viewpoint character. The idea became popular, and was borrowed by DC Comics. Because comics take generally shorter to produce than animation, she debuted in Batman #475 in March 1992, well before her animated debut in "Pretty Poison", which aired in September of that same year.
She is given a more extensive history in the comics. The daughter of immigrants from the Dominican Republic, Montoya is a fearless and intrepid police officer who works her way from uniformed cop to detective in the mostly male, mostly white G.C.P.D. She is partnered first with Bullock, then later with Detective Crispus Allen.
During the No Man's Land storyline, she becomes acquainted with Two-Face, who takes a fancy to her. Later, however, he realizes she is actually a lesbian, and Two-Face is angry enough to "out" her to the department. Renee served under the Major Crimes Unit with her partner and best friend Detective Crispus Allen, but after his murder by a crooked cop named Jim Corrigan, Renee Montoya left the force and her girlfriend Daria. After a bout with alcoholism, she is taken under the wing of Vic Sage, who trains her to succeed him as the new Question.
Montoya was first voiced by Ingrid Oliu for her first appearances in Batman: The Animated Series, then for the remainder of Batman and for The New Batman Adventures by Liane Schirmer, and in Gotham Girls by Adrienne Barbeau, who also voiced Catwoman.