This article contains spoilers from the most recent DCEU film. You have been warned.
Joining the GCPD
She is a long-time detective within the Gotham City Police Department, having regularly been passed up for promotion within the male-dominated organization, despite her proven skills and track record.
She has built an extensive case against the Black Mask, but Captain Patrick Erickson refuses to consider bringing the case to the D.A. due to Black Mask, a.k.a. Roman Sionis, being a powerful and influential crime lord and too big to move against. Meanwhile, she also pursues Harley Quinn after she blows up Ace Chemicals and unwittingly leaves behind a necklace given to her by the Joker. Her efforts eventually lead her to one Cassandra Cain, who has stolen and swallowed the Bertinelli Diamond, a valuable gem that is the key to unlocking the fortune of the Bertinelli Crime Family.
When Harley Quinn arrived at the Gotham City Police Department and busts Cain out of jail, she continues to pursue her. She eventually catches up with her at an abandoned waterpark amusement park, where she discovers that Quinn has taped Cain to a toilet and dosed her with laxatives in the hope of retrieving the diamond, which she had swallowed. She very nearly takes Quinn down, but soon discovers that there are multiple forces on both sides that are after Cain, including an entire small army hired by the Black Mask. She ends up teaming up with Quinn, Black Canary, the Huntress and Cain so that they can all get out alive. Her skills as a hardened and sharp-witted cop prove very valuable in the fight and the entire group makes it out alive, the Black Mask meets a watery and grisly end. Afterwards, she along with the Huntress and Black Canary use a portion of the proceeds from the fortune of the Bertinelli Diamond to form the Birds of Prey.
She is known for spouting lines which sound as they come out of '80s cop films. She harbors resentment against Captain Patrick Erickson for him having taken the promotion that should have been hers and taking credit for her achievements. Despite this, she is dogged and determined, pursuing her investigation into the Black Mask without the support of her teammates. Her sense of justice will not allow a wrong such as the Black Mask's criminal operation to go uncorrected. Despite her years of service to the Gotham City Police Department, she ultimately has it within her to quit when she realizes that she can no longer be effective as a force for good there.
- Expert Detective: Renee is a detective for the Gotham City Police Department and thus possesses associated skills. When finding Harley Quinn's "J" necklace she quickly deduce that she was unintentionally sending a message to the city of Gotham that they have broken up.
- Expert Combatant: As a police officer, Renee is highly trained in hand to hand fighting. She was able to fight Harley Quinn but wasn't able to best her due to her being slightly intoxicated and Harley's acrobatic skill. When fighting off Black Masks' thugs, she was able to take down a number of them with little effort.
- Stick Expertise: As a police officer, Renee is accomplished in using a baton in combat.
- Expert Markswoman: As a police officer, Renee is highly trained in using firearms.
- Police Baton: Montoya used this baton when fighting Black Mask's goons.
- Knuckle Dusters: Montoya used these brass knuckles when fighting Black Mask's henchmen.
- Glock: Montoya carried this handgun when working for the police force. However, after resigning, she was forced to give it up.
- Smith & Wesson Model 38 "Bodyguard": Rene used this snub-nosed revolver as her back up sidearm when going after Black Mask. She later gave it to Harley.
- Police Badge: She wore a badge that was the honor of the Gotham City Police Department, but like the gun was forced to give it up upon resignation.
- Harlequin Bustier: Rene wore a bustier that acted like a bulletproof vest that also looked like a Harlequin jester outfit during the Battle at the Booby Trap. This proved to be a smart move when she was shot in the chest by Black Mask, as she escaped with minimal injury.
- Renee is one of the few first LGBT characters of the DC Extended Universe.