"12 Angry Men" by Reginald Rose (in English)

Juror #8: Look, there was one alleged eye witness to this killing. Someone else claims he heard the killing, saw the boy run out afterwards and there was a lot of circumstantial evidence. But, actually, those two witnesses were the entire case for the prosecution. Supposing they're wrong?

Juror #12: What do you mean, supposing they're wrong? What's the point of having witnesses at all?

Juror #8: Could they be wrong?

Juror #12: What are you trying to say? Those people sat on the stand under oath.

Juror #8: They're only people. People make mistakes. Could they be wrong?

Juror #12: Well, no, I don't think so.

Juror #8: Do you 'know' so?

Juror #12: Oh, come on. Nobody can know a thing like that. This isn't an exact science.

Juror #8: That's right, it isn't.