|“||You're my girl. And my girl comes with me.||„|
|~ Mars to his hostage, Jennifer, while choking her.|
As his weapons of choice, he carried a Beretta 92FS Inox and a backup Para-Ordnance P-10. He was played by Ben Foster.
Mars first appears hanging out with his new friends, Dennis and Kevin Kelly, two other teenagers. They are hanging around a convenience store when they see a rich family pull up. Dennis, in an attempt to impress Mars, makes an obscene gesture to the teenage daughter, Jennifer, and she flips him off. Dennis is not happy with this and decides that he wants to steal the family's Cadillac. Kevin objects to this, but Dennis rebuffs him and follows the family home. They break into the garage and Mars points out a door leading to the house. Deciding that he wants to scare the daughter as revenge, the two break in and Dennis pulls his Beretta 92FS pistol on the daughter. Mars captures the young son, Tommy, and draws his Beretta 92FS Inox pistol when he hears someone at the door. It is just Kevin, however, who disobeyed his orders to stay in the pickup because he wanted to encourage them to leave. Mars holds his pistol on Kevin for several seconds, visibly intimidating him.
Because Tommy activated the silent alarm, a police officer arrives, only to be shot twice by Mars. Backup arrives, and although Mars gets into a violent shootout with police, he decides to go back inside. The hostages and their father, Walter, are tied up as leverage so the police don't enter the house, turning the robbery into a hostage situation. When the father protests, Dennis gets angry and pistol-whips him, giving him a brain injury. Dennis panics and phones the sheriff, Jeff Talley (Bruce Willis), who tries to negotiate with him. He negotiates the release of Walter so he can get medical attention for his head wound, and during the hostage transfer, Mars holds his pistol on Talley for a few moments before whispering "bang", and then slipping back away into the shadows. Later on, Talley successfully negotiates a hostage transfer that will give them the ransom and transport Dennis, Kevin and Mars away from the scene. However, Talley reviews tapes from a convenience store robbery where Mars shot the owner of the store and then watched him die, despite the clerk's persistent pleas for help. Talley realizes that he has been talking to the wrong guy and is worried that this will end in death like the previous hostage situation he was in control of.
Like he expected, everyone is ready to proceed with the transfer but Mars, who attempts to bring Jennifer along, who he has become infatuated with. When Talley attempts to stop the transfer, Mars holds his pistol to Jennifer's head and Talley hastily stops the transfer. Before he can negotiate a hostage release, however, he finds that he is too late. Mars has already killed both Kevin and Dennis because they were about to release the hostages. Meanwhile, Mars awkwardly attempts to show his affection for Jennifer, but these attempts come off as menacing to Jennifer, who is too scared to say anything. Mars lights up a joint and blows some smoke into Jennifer's mouth. Mars then says that when the police helicopter comes to pay the ransom, she will come with him.
When she objects, Mars begins to choke her and looks into her eyes with sad desperation, claiming that she is now his girl and she will come with him. When further attempts at a relationship are rebuffed, Mars ties her to a bed and attempts to rape her, although she gets away when Tommy holds a gun on him. However, the gun was on safety. Mars remarks "Safety first.", and he attempts to kill the two. Luckily, Tommy has untied one of Jennifer's ropes and she is able to stab Mars through the mouth with his own knife, buying them enough time to flee. Mars pursues them by crawling through the air ducts, and trails them to the home's panic room where he tries to fire through the bulletproof window. When this fails, Mars gives up and then writes "BUЯN it" on the glass in his own blood before promptly leaving. Mars then lights the entire house on fire by using liquor bottles as Molotov cocktails. Talley breaks in, knowing that he has to save the hostages before Mars kills them. Mars uses one of the cocktails to destroy Talley's squad car, but while killing the fake FBI agents with Molotov cocktails, he is shot in the stomach by the FBI team leader, Mr. Jones, who is later shot dead by Jeff Talley after being lit on fire by Mars. Mars, now weakened and completely covered in blood and resembling more of a demon than a man, looks at Jennifer regretfully one last time and before falling to his knees and dropping the Molotov cocktail on his head, burning himself to death.