Here are the details of the work. It was originally made for television in 1954 by Reginald Rose.
As the work opens up, there is case against a young man, who is charged with killing his father with a knife. The young man claims that he did have a knife, but he lost this knife. More importantly, he stated that the did not commit the crime. As you can see, the situation is rather tense. This is especially so, because the penalty for such a crime, if convicted, is the death penalty.
At first, all the evidence seems to point to a vote of guilty. The only juror that thinks that they young man might be innocent is juror 8. He has a pang of conscience. He has troubles sending a boy to death without more evidence and discussion. So, the men (jurors) debate the case further at the insistence of juror 8.
One by one, the jurors begin to change their minds in light of the evidence. After three acts of debating and looking at the evidence, the boy is acquitted.