How does Reginald Rose restore the audience's faith in the jury system as a means of achieving justice?
I think one of the most important ways in which the author of this excellent play cleverly restores the audience's faith in the jury system is by deliberately starting off the play with reference to the many criticisms that there are of the jury system. Note how, for some of the jury members, once they have to decide the fate of this young man some of them just want to get it over and done with as soon as possible. This is most crassly seen in No. 7:
Right. This better be fast. I've got tickets to The Seven Year Itch tonight. I must be the only guy in the whole world who hasn't seen it yet.
Thus Rose raises the problem with jury systems: the members might rush to a conclusion because of the inconvenience that it is to them and that they would not care about the fate of another fellow being.
However, as the play progresses, the jury moves from being 11 in favor of the accused being guilty to all accepting that each piece of evidence is doubtful and thus the accused cannot be, beyond all reasonable doubt, considered to be guilty. Each of the jury members is shown to be able to bring their own personal knowledge and experience to bear in the case and to thus create cause for reasonable doubt. Thus, having started off with such a negative impression of the jury and their ability to administer justice, Rose is able to turn it around and show a jury that has achieved justice through careful examination of the evidence provided. In spite of our fears, thanks to No. 8, the jury members have shown themselves to be obedient to the Judge's words at the beginning of the play:
I urge you to deliberate honestly and thoughtfully. You are faced with a grave responsibility.