12 Angry Men

This 1957 courtroom drama takes place in the jury room. From Wikipedia:

The story begins in a New York City courthouse, where an 18-year-old Hispanic boy from a slum is on trial for allegedly stabbing his father to death. Final closing arguments having been presented, a visibly tired judge instructs the jury to decide whether the boy is guilty of murder. The judge further informs them that a guilty verdict will be accompanied by a mandatory death sentence.^[7]

The jury retires to a private room, where the jurors spend a short while getting acquainted before they begin deliberating. It is immediately apparent that the jurors have already decided that the boy is guilty, and that they plan to return their verdict without taking time for discussion—with the sole exception of Juror 8 (Henry Fonda), who is the only "not guilty" vote in a preliminary tally. He explains that there is too much at stake for him to go along with the verdict without at least talking about it first. His vote annoys the other jurors, especially Juror 7 (Jack Warden), who has tickets to a baseball game that evening; and Juror 10 (Ed Begley), who believes that most people from slum backgrounds are more likely to commit crimes.

(via reddit)