The Brave One (2007)

Radio host Erica Bain and her fiancé Dr. David Kirmani are viciously attacked by three men while walking their dog in Central Park; the men record the assault on their phones and take Erica's engagement ring and her dog. David dies from his injuries, and Erica is unable to continue her life as normal. Traumatized and living in fear, she attempts to purchase a gun but is denied a sale due to having no gun license. A nearby black market gun dealer overhears her desperation and offers to sell her a Kahr K9 pistol. Unwilling to wait 30 days for a legal firearm, Erica buys the handgun from him. One evening while she is at a convenience store, a man enters and shoots the store's cashier to death. Hearing Erica's cell phone ring, the man stalks her in the aisles before she kills him with three shots. Another night on a subway car, two men harass the passengers, all of whom leave except Erica. The men then threaten her with a knife, but she kills them both. Later, Erica attempts to save a prostitute by threatening her pimp. When he attempts to run them down with his car, Erica shoots him in the head, causing his car to run over the prostitute. She is injured but lives. Fuelled by rage and a need for vengeance, Erica begins to track down the three men who killed David. Meanwhile, she strikes up a friendship with Detective Sean Mercer, who is investigating the vigilante killings around the city. The detective shares the name of a vicious criminal he is unable to prosecute. When the criminal is found dead near a parking garage, Mercer inspects the area and begins to suspect Erica. He takes her with him to interview the prostitute she had saved, but the prostitute does not let on that she recognizes Erica. Mercer privately indicates to Erica that he suspects her but is struggling with what to do about it. The police ask Erica to identify one of the suspects in her attack. Though she recognizes the assailant, she does not identify him. She is later informed that the police have found her engagement ring at a pawn shop and goes there to get a name, address, and phone number of who sold it to them. She tracks down one of her attacker's ex-girlfriends, who sends Erica the video recording of her attack and his address. Erica forwards the video to Mercer. Erica tracks down all three men and confronts and kills two of them before freeing her dog. She struggles with the third attacker, who gains the upper hand just as Mercer arrives. As Mercer attempts to arrest the attacker, Erica retrieves her weapon and prepares to execute him. Mercer persuades Erica to lower her gun, but after looking into her pleading eyes, hands her his own gun to use instead, and Erica shoots the attacker dead. Mercer then insists that Erica wound him with her gun, which she does, allowing them to frame her attackers for the vigilante killings. Mercer then places her gun in the last attacker's hand, and Erica walks away through Central Park joined by her dog.