Stain of Guilt begins with Quincy (Jack Klugman) serving as a technical contributor on a movie set where the script is based on a highly publicized case of a wife, Victoria Sawyer (Carolyn Jones), who was convicted of murdering her husband. During filming, Quincy notices some contradictions in the evidence which lead him to believe that there was a staging of the crime scene and Victoria might be innocent. Quincy teams up with a defense lawyer, Cassie Spencer (Susan Powell), to try and have the case reopened while also investigating who committed the crime, but he comes up against big obstacles with the District Attorney's office and a tough judge, not to mention the producer of the movie who wants to complete the project based on the conviction.
This is a good murder mystery episode and such a refreshing change from prior Season 6 episodes which have mainly dealt with social problems and public health issues. Here we have a crime committed by an unknown party, a compelling investigation with plenty of suspects, good guest star performances, the big reveal which features a twist, and then a nice, light-hearted scene at Danny's as the conclusion to end things on a positive note. This episode is an example of everything I like about the Quincy series and I just wish more of the plots in the latter seasons were like this.
We see several familiar faces returning to the series as guest stars in this episode including Carolyn Jones, Ed Begley Jr. and William Sylvester who have all previously appeared in different roles. I thought Carolyn Jones gave a particularly good performance as the wrongly convicted woman who has been languishing in jail and given up hope that she will ever be freed. Sadly, this is among her final performances before her untimely death from colon cancer in 1983.
Overall, this is a quite interesting, entertaining and enjoyable Season 6 murder mystery episode of Quincy which I highly recommend viewing.