Character Analysis
The main things you need to know about Juror #10 are that he has a bad cold and that he's a total racist. The first taste we get of his prejudice comes when he tells Juror #7, "It's tough to figure, isn't it? A kid kills his father. Bing! Just like that. Well, it's the element. They let the kids run wild. Maybe it serves 'em right."
At first, we might not be quite sure of what the guys means when he says "the element." But chances are that he's referring to a general group of people, which tells us right off the bat that he's not really one for specifics... or for sympathy and understanding.
The more we hear from Juror #10, the more we realize how ignorant he is. Worse yet, the guy seems to think that if he just says more racist stuff, he'll somehow get everyone to come over to his side. Eventually, he launches into one final rant, shouting, "Well, don't you know about them? There's a... There's a danger here. These people are dangerous. They're... wild. Listen to me. Listen to me."
The "people" he's talking about here, of course, are people of color. It's a good thing that by this point in the movie, no one is willing to listen to this guy. So he gives up and goes to sit in the corner of the jury room, hanging his head in shame.
Good riddance, really.