4th Juror has a valid arguement, as he carefully lays out all of the evidence of the knife to convince 8th Juror with seven, linear, factual points. His arguement is valid because he uses rationale, he doesn't jump to conclusion, his vote is based on the evidence.
NO. 4: The boy admits going out of his house at eight o'clock after being slapped by his father.
NO. 8: Or punched.
NO. 4: Or punched. He went to a neighborhood store and bought a switch knife. The storekeeper was arrested the following day when he admitted selling it to the boy. It's a very unusual knife. The storekeeper identified it and said it was the only one of its kind he had in stock. Why did the boy get it? (Sarcastically) As a present for a friend of his, he says. Am I right so far?
NO. 8: Right.
NO. 3: You bet he's right. (To all) Now listen to this man. He knows what he's talking about.
NO. 4: Next, the boy claims that on the way home the knife must have fallen through a hole in his coat pocket, that he never saw it again. Now there's a story, gentlemen. You know what actually happened. The boy took the knife home and a few hours later stabbed his father with it and even remembered to wipe off the fingerprints.
[The door opens, and the guard walks in with an oddly designed knife with a tag on it. NO. 4 gets up and takes
it from him. The guard exits.]
NO. 4: Everyone connected with the case identified this knife. Now are you trying to tell me that someone picked it up off the street and went up to the boy's house and stabbed his father with it just to be amusing?
NO. 8: No, I'm saying that it's possible that the boy lost the knife and that someone else stabbed his father with a similar knife. It's possible.
[NO. 4 flips open the knife and jams it into the table.]
NO. 4: Take a look at that knife. It's a very strange knife. I've never seen one like it before in my life and neither had the storekeeper who sold it to him.
[NO. 8 reaches casually into his pocket and withdraws an object. No one notices this. He stands up quietly.]
NO. 4: Aren't you trying to make us accept a pretty incredible coincidence?
