The first version I saw of this story is actually the 1997 TV movie which we watched in school. I have since seen the 1957 movie, which was nominated for Best Picture, Best Director, and Best Adapted Screenplay. I like both.
This was another taped play from LA Theatre Works which did the Importance of Being Earnest play I listened to earlier this year. The issue with this play as being a radio play is that it features (as the title suggests) twelve men. They do have different voices, but identifying each one consistently is difficult and I don't recommend. The story is as always fantastic and I do wish I could see the actual production.
If you are not aware of the plot, it's about a jury who will determine whether a young man murdered his father. If found guilty, he will go to the electric chair. After the first vote, it is 11-1. And so starts a discussion about the evidence presented and the personalities and backgrounds of the different men.
If you haven't seen any of the adaptations, correct that immediately.
The play did have a nice after part with an interview with the author of the original teleplay's wife. He unfortunately passed years ago, but he sounds like an interesting person and the idea for the play was actually from his own jury experience.