|Full Name||Joe Flynn (real name)|
|Appearances||"The Blue Butterfly"|
|Portrayed by||Chad Everett|
Jerry Maddox, alias for Private Investigator Joe Flynn who faked his own death back in 1947 with Vera Mulqueen, now his wife Viola. He posed as the former bartender for the Penny Baker Club.
In 1947, Joe was hired by a girl named Sally to locate her sister, Vera Mulqueen, who had fled to New York City in one of its clubs, but requested that he not tell her Sally is looking for her. Eventually, after searching every club in the city, Joe came to the Penny Baker Club and was able to identify Vera. However, he also fell in love with Vera, which was dangerous, since she was the moll of Tom Dempsey, an infamous mobster, who dispatched his two henchmen on Joe. Joe was briefly ruffed up before being thrown out of the club.
Despite this, Joe continued to see Vera over the next five days as they started an affair. However, when they were caught by Dempsey's enforcers, Betsy Sinclair, the club singer, managed to bail him out by claiming that Joe was her man. Joe then began to agree with Betsy's concerns of Dempsey finding out. Vera suggested that they elope and take the Blue Butterfly necklace she wears, but Joe found it too risky with Dempsey's thugs constantly tailing her.
Vera then mentioned that when she's not wearing the necklace, Dempsey keeps it in a secret safe which she knows the location of. Joe spent a few days brainstorming how to crack the safe but ultimately judged it impossible. Summoning Vera to his office, he devised a plan for her to slip out with the Blue Butterfly while Dempsey and the entire club were focused on listening to a boxing match on the radio. However, his secretary deplored the plan and inadvertently forced Joe to admit to Vera that Sally was looking for her, only to learn that Vera had no sister named Sally.
Despite the confusing revelation, the two went forward with the plan. But when it seemed like they were home free, they were confronted by Sally and her husband Lenny. It turns out that Sally was Dempsey's daughter, whose mother committed suicide when Dempsey cut them off financially after taking Vera as his girl. Sally only hired Joe to get Vera away from Dempsey so she could take her revenge. However, Lenny first made a grab for the Blue Butterfly, but Joe grappled with him. While they struggled, Sally accidentally shot Lenny, before fighting with Vera over the gun and she accidentally shot herself. Knowing they had to disappear, Joe toss the bodies into his car and lit it on fire, knowing that the police would mistake them for Joe and Vera.
Vera then had an epiphany, believing the necklace to be cursed. Declaring that he only loves her, Joe wraps up the Blue Butterfly and hides in a slot where he dislodged a brick from when they first met, so that Dempsey would never know that his prized possession was under his nose.
Over the intervening sixty years, Joe and Vera changed their names to Jerry and Viola Maddox and had four children, seven grandchildren and two great-grandchildren. By 2012, when Betsy passed away, Jerry went to her funeral to pay his respect. He was then questioned by Stan Banks, who was on the trail of the Blue Butterfly, as to his association with Sinclair. Jerry lied and told him he was the club's bartender. Stan soon left after being spotted by Tom Dempsey III
But Stan later figured out the truth and confronted the Maddoxs, threatening to expose them if they did not tell him where the Blue Butterfly was. The Maddoxs gave into his demand and told him the necklace's hiding place. However, their caretaker, Frankie Hunsacker, Joe's secretary's great-grandson, was also hunting for the necklace, and upset that Stan was able to bully its location out of them whereas he was attempting to slowly coax it out of them, grabbed their gun and confronted Stan, accidentally shooting him.
A few days later, Beckett and Castle came by the Maddoxs regarding Stan's death. Castle then asked about Sally. Jerry made up a story that about him being the bartender and that Sally turned up sometime after Dempsey's funeral and disappeared afterwards. However, the crime-solving duo were able to deduce his lie and they too learned their secret. They confronted the Maddoxs, accusing them of murdering Stan. However, Jerry realized it was Frankie when he made a grab for their gun, but Beckett was able to arrest him.
Beckett and Castle later revisited the Maddoxs regarding the truth around Sally and Lenny's deaths. Once the Maddoxs told the truth, they presumed they were under arrest, but Beckett judged their actions to be in self-defense and that they're no longer the people they once were in 1947.
Castle then asked why they didn't take the Blue Butterfly. Jerry explains that the family they have and their love for one another is more valuable than any necklace.
In Castle's imagination while reading the diary of P.I. Joe Flynn, he pictures himself as Joe.