A courtroom at the New York County Courthouse. As a jury of 12 men assembles, the judge tells them that they have examined a case of first degree premeditated murder, and that they must now deliberate to come up with a verdict. We see the members of the jury as the judge tells them, "If...there's no reasonable doubt, then you must, in good conscience, find the accused guilty." He then tells them that their verdict must be unanimous. Finally, he tells them that the death sentence is mandatory in this particular case. After the alternate jurors are excused, the jury goes off to another room to discuss, as a young man, the defendant, watches them go. We see the young man's face in close-up as somber music plays.
The jurors meet in the next room. One of them, Juror 7, offers another, Juror 8, a piece of gum, but he declines. Another Juror, Juror 6, tries to open the window, as Juror 7 tells him that it's supposed to be the hottest day of the year. A court official assembles the group and goes outside to wait.
A juror locks the door, as a man assembles cards so they can vote by ballot. Juror 3 asks Juror 2, a meek man, what he thought, and tells him he thought he was going to fall asleep. "I've never been on a jury," Juror 2 says, and Juror 3 tells him he's been on many juries. Juror 3 suggests that he thinks it's an open-and-shut case, but they insisted on talking a lot. "It's a system, they're entitled, but if you ask me, I'd slap those tough kids down before they start any trouble," Juror 3 says.
Juror 3 encourages everyone to get started. Juror 12 stands and talks to Juror 8, saying they are lucky to have gotten a murder case, as it's much more interesting than assault or theft cases. He then points out the Woolworth Building and notes that it's strange he's never been inside.
Juror 7 talks to Juror 10, who has a hot-weather cold, before going to Juror 1, the jury foreman, and telling him to start the meeting, even though there's someone in the bathroom. Juror 4 reads a newspaper and tells Juror 3 that he is an analytical stock broker. Juror 3 tells him that he runs a messenger service called The Beck and Call Company, that the name was thought up by his wife, and that he has 37 employees.
Juror 1 assembles the group at the table. Juror 7 says he wants to get out of there quickly, since he has tickets to a baseball game between the Yankees and Cleveland. When Juror 1 tells them they ought to sit in numerical order around the table, there is already indecision, with some men suggesting that it makes no difference where they sit. In spite of this conflict, they sit in order, as Juror 12 tells another juror he thought the prosecuting attorney was "really sharp."
Everyone takes a seat except Juror 8, who is standing at the window looking at the street outside. We learn through some chattering that the case involves a young man who has been accused of killing his father. When they've all assembled, they realize that Juror 9 is not there yet, and one of them goes to fetch him.
As Juror 9 takes his seat, Juror 1 says they can handle the process any way they see fit. On Juror 7's suggestion, they take a vote to see where everyone stands. 11 of them raise their hands saying they think the defendant is guilty, but Juror 8 does not. 8 raises his hand for "not guilty," as Juror 10 shakes his head and says, "There's always one."
They turn to Juror 8 and ask him if he really thinks the defendant is innocent. 8 says, "I don't know," to which 3 replies, "You sat in court with the rest of us. You heard what we did. The kid's a dangerous killer, you could see it." 8 insists that the kid is only 18 years old, but 3 suggests that he definitely stabbed his own father, "four inches into the chest."
The other jurors try to get 8 to see their point of view, but he remains ambivalent, and suggests that he wants to talk about it first, if the outcome will be that they are sending a boy off to die. "Couldn't change my mind if you talked for 100 years," says 7. 8 wants to entertain the possibility that they are wrong, and suggests that they should take an hour, since the baseball game he wants to watch doesn't start until 8 o'clock.
The rest of the jurors agree to sit in the room for an hour. 8 reviews the facts: "Look, this kid's been kicked around all of his life. You know, born in a slum, mother dead since he was 9. He lived for a year and a half in an orphanage when his father was serving a jail term for forgery. That's not a very happy beginning. He's a wild angry kid, that's all he's ever been. And you know why? Because he's been hit on the head by somebody once a day, every day. He's had a pretty miserable 18 years, I just think we owe him a few words, that's all."
10 says that they don't owe the defendant anything, since he got a fair trial already. He then stands and suggests that the boy was a born liar, which angers 9, who says that no one has a monopoly on the truth. 12 shows the other jurors a picture of the product he works on at his advertising agency: Rice Pops. He tells them he wrote the ad copy, "The breakfast with the built-in bounce."
Juror 1 asks 8 why he has his doubts, and then asks each juror to say why he thinks the defendant is guilty. 2 is very soft-spoken and hesitant and suggests that he thinks that he had to have to done it. "The burden of proof's on the prosecution. The defendant doesn't even have to open his mouth," 8 says. When he gets his chance to speak, 3 wants to address the facts: that the old man lived downstairs under the apartment where the murder happened, that he heard loud noises at 12:10 on the night of the murder, that he heard the kid yell 'I'm going to kill you,' and that after he heard the thud of the body hitting the floor, he opened his apartment door to see the defendant running out of the house.
4 suggests that the defendant's story, that he was at the movies during the time of the killing, but couldn't remember which movies he saw, was unconvincing. 10 and 11 chime in, reminding 8 about the woman across the street who alleges to have actually seen the killing. 8 counters that she only saw the killing through the windows of a passing train, but 10 insists that they proved that one can see through the windows of a train.
8 pointedly asks 10 why he believes the woman's story, but not the boy's, since she is just as untrustworthy as the boy—coming from the slums—according to 4's logic. "She's one of them too, isn't she?" 8 says, and 10 gets annoyed by the question, unable to supply an answer.
5 asks to pass, and 6 says he was looking for a motive, and was convinced by the testimony of the neighbors who live across the hall from the defendant. "Didn't they say something about a fight, an argument between the old man and his son around about 7:00 that night?" he says. 8 clarifies that they heard an argument at 8, but that they could not hear what it was about. He also says that the neighbors heard the father hit the boy twice, and saw the boy run out of the apartment, but that that does not supply an actual motive for the boy.
The film drops the viewer in the middle of the narrative, as the first scene takes place immediately before a jury is about to assemble to decide on a verdict. We do not see any of the case itself, but we learn from the judge that they are there to decide on a murder case. By starting the story in the middle of a case, Reginald Rose, the screenwriter, shows us that the story is going to concern the jury itself and the ways that assembled strangers make judicial decisions. We are going to be thinking about the court case not in terms of the actual performances of the lawyers, but from the perspective of those who have a backstage role in the court process, the jury.
Even if the viewer is not up to speed on all the expository details of the case from the start, the stakes are high. As the judge outlines, the jury must come to a conclusion unanimously, and if the defendant is found guilty, "the death sentence is mandatory in this case." The fact that the jury's decision could result in the death penalty only makes their deliberation that much more important, and director Sidney Lumet shoots the jury members' faces one-by-one as we learn these important terms.
While it would appear that the jurors have a simple task ahead of them, as we are introduced to them one by one, we see that they are a diverse group of men, and that reaching unanimity might be harder than expected. The jurors come from a wide range of class backgrounds and careers and think about the different elements of the case from different perspectives, which seems sure to complicate the process of deliberation—especially after the initial vote is not unanimous.
Indeed, the reason the vote is not unanimous is the dissent of a single man, Juror 8. While all of the jurors, different though they may be, raise their hands suggesting that they think the defendant is guilty, he stays quiet. The image of the tableful of tie-wearing men staring at him in disbelief is a striking one. In effect, he is the single character constituting the film itself; were he to vote along with the other jurors, the film would be over immediately. Instead, his decision necessitates that they have a lengthy discussion about their respective beliefs.
Juror 8 is resistant to agreeing with his fellow jurors not because he is sure that the boy did not commit the crime he is alleged to have committed, but because he is ambivalent, unsure, and cautious about going along with the prevailing opinion just for the sake of it. When they ask him if he believes the defendant's story, he tells them, "I don't know whether I believe it or not," and when they ask him what he wants to do, he tells them he just wants to talk. Juror 8's position is one of complete indecision and ambivalence, and rather than make a snap judgment about his perception of the case, he wants to utilize the process of judicial debate and discussion and exercise their rights to deliberate thoughtfully as jurors.