Showgirls

Nomi Malone is a young drifter who hitchhikes to Las Vegas hoping to make it as a showgirl. After being cheated of her money by her driver, Nomi meets Molly Abrams, a seamstress and costume designer who takes her in as a roommate. Molly invites Nomi backstage at Goddess, the Stardust Casino show where she works, to meet Cristal Connors, the diva star of the topless dance revue. When Nomi tells Cristal she dances at Cheetah's Topless Club, Cristal derisively tells her that what she does is akin to prostitution. When Nomi is too upset to go to work that night, Molly takes her dancing at The Crave Club. After getting into a fight with James, a bouncer at the club, Nomi is arrested. James bails her out of jail, but she pays him little notice.
Shortly thereafter, Cristal and her boyfriend Zack Carey, the entertainment director at the Stardust, visit Cheetah's and request a lap dance from Nomi. Although the bisexual Cristal is attracted to Nomi, her request is also based upon her desire to humiliate Nomi by proving she is little more than a prostitute. Nomi reluctantly performs the lap dance after Cristal offers her $500. James happens to be at the strip club as well and witnesses the lap dance. He visits Nomi's trailer the next morning and, like Cristal, tells Nomi that what she is doing is no different from prostitution.
Cristal arranges for Nomi to audition for the chorus line of Goddess. Tony Moss, the show's director, humiliates Nomi by asking her to put ice on her nipples to make them hard. Furious, Nomi leaves the audition and again runs into James, who says he has written a dance number for her and contends that Nomi is too talented to be a stripper or showgirl. Despite her outburst at the audition, Nomi gets the job and quits Cheetah's. Cristal further humiliates Nomi by suggesting she make a "goodwill appearance" at a boat trade show which turns out to be a thinly disguised form of prostitution. Undeterred, Nomi sets out to get revenge against Cristal and claim her mantle. She seduces Zack, who secures an audition for her to be Cristal's understudy. Nomi wins the role, but when Cristal threatens legal action against the Stardust, the offer is rescinded. After Cristal gloats and taunts Nomi at a performance, Nomi pushes her down a flight of stairs, and Cristal breaks her hip. Unable to perform, Cristal is replaced by Nomi as the show's lead.
Although Nomi has finally secured the fame she sought, she alienates Molly, the only one who witnessed her push Cristal. Later, Molly relents and attends Nomi's opening night at a posh hotel, where she meets her idol, musician Andrew Carver. Carver lures Molly to a room, where he brutally beats her and helps one of his bodyguards rape her. Molly is hospitalized after the assault. Nomi wants to prosecute Carver, but Zack tells her the Stardust will bribe Molly to quiet her in order to protect their celebrity client. Zack then confronts Nomi with the details of her sordid past: her real name is Polly, and she became a runaway and prostitute after her father murdered her mother and then killed himself. She has been arrested several times for drug possession, prostitution, and assault with a deadly weapon. Zack blackmails Nomi by vowing to keep her past quiet if she will not press charges for Molly's assault.
Unable to obtain justice for Molly without exposing her own past, Nomi decides to take justice into her own hands. She gets Carver alone in his hotel room and beats him bloody. Nomi then pays two hospital visits; one to Molly to deliver news of the assault and let her know that Carver's actions did not go unpunished, and another to Cristal to apologize for injuring her. Cristal admits she pulled a similar stunt to get cast in the lead of a show years before. Because of her world-weariness, and the fact that her lawyers managed to secure her a large cash settlement, Cristal forgives Nomi, and they exchange an 'It's all good' kiss. Nomi leaves Las Vegas and hitches a ride to Los Angeles, coincidentally with the same driver who earlier stole her possessions when she arrived. Nomi pulls her knife, and says "I want my fucking suitcase," as they pass a billboard advertising Nomi, and the film fades to credits.

Question: Who decide to take justic into Molly's hand in this movie?
Answer: Nomi