After being written init was re-created at least a further three times at different stages in history with extremely minor differences.
Prejudice Rose notes in the stage directions how the Guard constantly locks and unlocks the room. Judge P3. Rose deliberately constructs a parallel personal story for the 3rd Juror, whose broken relationship with his year-old son, influences his decision.
Juror number 4 based his decision based on the fact that the boy on trial grew up in the slum. Lumet is signaling to viewers that the makings for personal prejudice and bias towards this young boy are perhaps in the works, as deliberations unfold among the jurors.
Lumet gives us a glimpse of the young boy on trial for murder, he appears to be Hispanic and perhaps unlearned and underprivileged. Their one and only goal is to decide unanimously whether or not the This is a case in which a decision was apparent to be reached easily, all the jurors would presume the defendant guilty of murdering his father, but only one takes an exception and votes as not guilty.