Here's the death of detective Matt Spicer during Criminal Minds season 5 explained, and who killed him. Criminal Minds followed an elite unit of FBI agents dubbed the Behavioral Analysis Unit, who are tasked with capturing serial killers. During the 2000s, the show was one of several procedurals that sought to inject a little freshness into the well-worn genre by taking different approaches. CSI used science and technology to add some spice, while Criminal Minds focused on psychological profiling.
Naturally, focusing on killers and their methods made for some grim storylines in Criminal Minds, which could often make for disturbing viewing. Luckily, the show featured a very likable cast, including Shemar Moore - who left during season 11 - Matthew Gray Gubler and Kirsten Vangsness. The series ran for 15 seasons in total, coming to a close in 2020. A revival series is already in the works, however, which appears to be reuniting much of the original cast.
Few killers on Criminal Minds disturbed viewers quite like Billy Flynn, AKA the "Prince of Darkness." Played by Tim Curry, Flynn was a serial killer who would strike during blackouts, breaking into homes and assaulting and murdering families - but leaving survivors behind who witnessed his killings. One such survivor was a future detective named Matt Spicer (Eric Close, Dark Skies). When Spicer was a boy, Curry's "Prince of Darkness" broke into his home, tied up Matt's parents and his baby sister and made them watch as he assaulted their mother Sylvia and then murdered her and her husband. Since he was so young, his grandparents tried to convince Matt his parents died in an accident, but once Spicer is assigned to work with the BAU to track down a resurgent Flynn, the memories come back.
This set Spicer up as one of Criminal Minds' most tragic supporting characters, as the fate he escaped decades prior came back around in the most horrific way. Spicer has a daughter of his own named Ellie, so once he and Morgan realize Flynn is recreating his crimes, they believe the killer will kidnap her. The detective and Moore go to his parent's former house to find both his daughter Ellie and sister Kristin are being held hostage. Moore's Morgan - who was in Sonic The Hedgehog 2's cast - is also captured and forced to watch as Flynn makes Matt Spicer get on his knees and executes him in front of his family.
Moore later kept his promise to Spicer before he died that he would keep Ellie safe. After Flynn abduced Ellie, Moore eventually tracks them down and shoots Flynn dead. The serial killer was based on the real-life crimes of "Night Stalker" Richard Ramirez, so it's fitting this story was one of Criminal Minds' darkest. While Close's Matt Spicer only appeared in one episode, his death left an impact on Moore, who kept in touch with Ellie in the aftermath.