Task: Question Answering
Input (English): Passage: During the rage of Hurricane Katrina, Detective Andy Devereaux discovers the body of his former partner in a close to underwater warehouse. Quickly forgetting about his discovery, he joins a newly transferred detective named Stan Johnson (Curtis "50 Cent" Jackson) trying to end a conflict involving looters. 
Post-Katrina, Andy and Stan are now partners. They work with corrupt detectives Pepe and Barney, who are caught up in the murder of an undercover narcotics agent. Investigating the escalating police corruption in New Orleans is FBI Agent Brown. Brown brings up his thoughts to Police Captain Friendly who insists he is doing his best to solve the problems in his department.
Meanwhile, police therapist Nina Ferraro tries to help the detectives with their struggles, with little avail. She is particularly interested in Andy, whose father, also a detective, was murdered in the line of duty. 
Things are complicated further with Agent Brown's investigation into Andy and his crew. Brown tells Andy that he has an informant who is leaking out the details, and Andy, disbelieving at first, begins to resign himself to the fact that one of his men is betraying him. 
After Captain Friendly is assassinated by a local gangster named Chamorro, Andy, Stan, Pepe, and Barney decide to take the law into their own hands and go after Chamorro. While interrogating Chamorro, they find out that Brown has been supplying the drug dealer with information about the police raids, to help his own investigation. In a violent shootout, Barney accidentally shoots and kills Pepe.
Andy and Stan escape, only to return to the warehouse where they met. There Andy realizes that Stan is the informant. After the two start arguing, Brown shows up and there is another shootout, ending in Brown's death. Andy comforts a sobbing Stan, then Andy kills his partner, as he possibly did with his previous one. 
Question: What is the last name of the person that Andy kills?
Output (English): Johnson.