why did rose end act 1 with the 8th juror saying, " you don't really mean you'll kill me, do you ?"

8TH JUROR: But supposing he really did hear it. This phrase, how many times has each of us used it? Probably hundreds, "I could kill you for doing that, darling." "If you do that once more, Junior, I'm going to kill you." "Come on, Rocky, kill him." We say it every day. It doesn't mean we're going to kill someone. 3RD JUROR: Shut up, you son of a bitch! Let me go, God damn it! I'll kill him! I'll kill him! 8TH JUROR: You don't really mean you'll kill me, do you?

These two complimentary moments mark a turning point in the argument. The conflict between 3rd Juror and 8th Juror reaches a boiling point, and 3rd Juror attacks him. However, what he inadvertently does is prove an earlier point of 8th Juror. This further serves to intensify the conflict between the two, further casting them by Rose as the protagonist and antagonist, which conflict continues to be a massive obstacle for 8th Juror. Furthermore, what it does for the audience and for the other jurors is to completely ruin the credibility of 3rd Juror as an impartial observer and juror. 8th Juror has managed to make 3rd Juror look like a mad man to the other jurors, and he becomes increasingly less effective in his efforts to maintain support throughout the second act.