Patti Sue Diamond (Florence Henderson; 1934-2016) is the main villainess of "Ballad for a Blue Lady," episode 7.09 of Murder, She Wrote (airdate December 2, 1990). She was a blues singer and the wife of country star Bobby Diamond, as well as the stepmother of Alice Diamond and an old friend of Jessica Fletcher.
A few days prior to the episode's events, Patti Sue learned that Bobby had found a woman who "made him feel young again" and was planning to leave her, as she had received a two-page letter written by Bobby where he stated those exact sentiments. Patti Sue turned heel following the revelation and planned to kill Bobby; knowing her husband's habits, the vengeful villainess laced a bottle of Bobby's favorite bourbon with strychnine and placed it in his farmhouse prior to leaving for a concert that she was singing at. As Patti Sue expected, the country star died after he drank the poisoned bourbon, and to make sure she had a good alibi, she called Bobby at 10:30 PM during the concert's after-party, purportedly making sure that he had his nightly drink. When he didn't answer her call, the villainess realized that her murderous plot was a success.
An hour later, Patti Sue left the after-party and went home, making a stopover at the farmhouse in order to confirm her suspicions. After she saw her husband lying dead on the floor, the former later set up the crime scene to appear to be the site of a suicide by placing the bottle of strychnine next to the bottle of bourbon and also leaving the second page of his letter behind to make it appear that said page was Bobby's suicide note. In order to make sure that the Nashville Police Department could not connect the "suicide note" to her late husband's letter, Patti Sue cut off the top third of the second page, which featured the logo of the Diamonds (a musical ensemble that Bobby was once a part of) and also had the number "2" written at the top right-hand corner. Just as the villainess prepared to leave, she noticed that Bobby's tape recorder was in operation, and not wanting his "death agony" to be his final recording, Patti Sue took the tape with her and then tossed it into a creek while she was heading home.
Her reveal as Bobby's killer ironically came after her greedy and villainous stepdaughter (who had turned heel upon realizing that her stepmother would inherit the business) attempted to kill her twice by first poisoning her coffee and then poisoning her intravenous therapy drip while she was hospitalized, as it was Alice's plan to make it look like her stepmother killed her father and then killed herself out of guilt that led to the truth being uncovered. The murderous blues singer survived both attempts on her life due to having eaten a big bowl of ice cream earlier, which lined her stomach, and furthermore, Jessica deduced Patti Sue's role in Bobby's death after Alice showed the "suicide note" to her, Preston Wardell (Alice's boyfriend), and Lieutenant Jackson, with the missing top third of the page serving as the incriminating piece of evidence against her. Back at the hospital that the villainess was laid up in, Jessica convinced her old friend to confess to murdering Bobby, which she did. Additionally, Patti Sue tearfully expressed her belief that she had ruined her friendship with Jessica after the latter expressed her sorrow for the former, and was subsequently arrested offscreen.
- "(Jessica: "You must be carrying a terrible burden. Don't you think perhaps... you should get rid of it now?") That letter Bobby wrote... said our marriage was over; that he'd found some girl who made him feel young again. He didn't have the guts to tell me to my face. I couldn't believe it! I kept reading that letter over and over again... and then I realized that the second page was just like one of Bobby's cornball song lyrics, and a perfect 'suicide note!' Damn it, Jessica! I'd given too many years to that ornery man. I wasn't gonna let him throw me away like yesterday's newspaper! (Jessica: "And that's when you decided to kill him.") Bobby had to have his nightly glass of 'what made the South the South' no matter where he was... so I loaded up a bottle of bourbon with some strychnine... and took it out to the farmhouse that morning. I knew he'd stop by later like he did every day. I guess it was their place. When he poured himself a drink that night, it was loaded with poison. I called him from the hotel to make sure he hadn't forgotten to have his drink. When he didn't answer... I knew he was already dead. I even asked you the time... just to make certain I'd have a real good alibi. (Jessica: "10:30.") Then we went back to the party, and... I went home at 11:30—only I made one stop on the way at the farmhouse to put everything in order. I put the bottle of poison on the table beside the bourbon... and the 'suicide note' next to the poison. I was just about to leave when— when I noticed Bobby's tape recorder was still on. I didn't want Bobby's death agony to be his last recording, so I... took the tape with me, and tossed it in the creek on the way home. I was sure I'd done a good job of making it look like suicide! Along came Alice, and... make it look like murder again! It's almost funny, ain't it?" (Patti Sue's confession to murdering Bobby)
- "(Jessica: "I am so sorry.") Hey! Cut that out. Singing the blues is my thing, and I— I do it real good. I guess I forgot that you do your thing real good too. I've made a terrible mess of things, didn't I?" (Patti Sue tearfully confessing her belief that she ruined her long-term friendship with Jessica because of her villainous deed)