Juror #3 flips out on Juror #7, saying that the whole room is descending into nonsense.
Juror #8 (Fonda) says he'd like to see a diagram of the boy's apartment to see if there are any cracks in the story of the old man who saw the boy flee the scene of the murder.
Apparently, the old man couldn't walk well because of a stroke he'd had the year before. Yet he would have had to get from his bed to his apartment building's hallway in 15 seconds to see what had happened. Juror #3 says they shouldn't take the 15-second time-frame too seriously, because the man was old and probably confused. But of course, this is the same reason why they shouldn't put too much stock in the old man's testimony.
Juror #8 recreates the same dimensions of the old man's bedroom and apartment hallway. The others think he's wasting their time, but he can only cover the distance in 41 seconds while the old man was supposed to have done it in 15. So the new story is that the old man heard the boy fighting with his dad earlier in the night, heard the body hit the floor above his apartment, rushed to the door and assumed the boy was running away.
At this point, Juror #3 flips out again and says they should send the boy to the electric chair. But Juror #8 accuses him of wanting the boy dead simply because he doesn't like the boy. Juror #3 goes after #8 and says he's going to kill him, but as #8 reminds us all, we say stuff like that all the time without meaning it, which is no doubt what the boy was doing when he said it to his father.