Please answer the following question: Build a movie plot around this: Why does Cody turn himself in? to provide perfect alibi
Answer:
Cody Jarrett (James Cagney) is the ruthless, deranged leader of a criminal gang. Although married to Verna (Virginia Mayo), Jarrett is overly attached to his equally crooked and determined mother, 'Ma' Jarrett (Margaret Wycherly), who is his only real confidant. When he has one of his splitting headaches she consoles him, sits him on her lap and gives him a drink with the toast "Top of the world". Jarrett's father died in an institution. He himself is described as someone who when "he was a kid, he used to fake headaches to get his mother's attention away from the rest of the family. It worked. As he grew up, the fancied headaches became real, until now they tear him to pieces."Jarrett and his gang carry out a major robbery involving the hijacking of a train and the deaths of several people, including four members of the train crew and one of his own accomplices, Zuckie (Ford Rainey). With the help of informants, the police soon close in and Jarrett shoots and injures US Treasury investigator Philip Evans (John Archer). He escapes to Illinois and confesses to a lesser crime which was committed by an associate. It was done at a time to coincide with the train robbery and thus provides Jarrett with a perfect alibi. He is sentenced to one to three years of jail time.Evans is not fooled however. He allows Jarrett's conviction to go through but then sends an undercover agent into the penitentiary in order to get information from Jarrett as part of a sting operation. The agent is Hank Fallon (Edmond O'Brien), who goes by the name "Vic Pardo." His main task is to find the "Trader", a fence who launders stolen US Dollars on the European black market on Jarrett's behalf.'Big Ed' Somers (Steve Cochran), Jarrett's ambitious right-hand man, has designs on both Jarrett's gang and his treacherous wife Verna. He orders another convict, Roy Parker (Paul Guilfoyle), to kill him. In the prison workplace, Parker arranges to drop a heavy piece of machinery on Jarrett, but Fallon/Pardo pushes him out of the way and saves his...