What Happened to Glenn Quinn in 2002? Inside the Actor’s Untimely Death at 32

Glenn Quinn was best known for playing Mark Healy on Roseanne and Doyle on Angel, the Buffy the Vampire Slayer spinoff. Years later, when Roseanne returned to television, and The Conners followed, some viewers realized his character wouldn’t be coming back — and started asking why.

For many fans, the 2018 revival of Roseanne sparked a heartbreaking question: What happened to Glenn Quinn? While the actor had been off-screen for years, the reboot made it clear his absence on the screen wasn’t a casting choice.

Glenn was found dead on Dec. 3, 2002, at a friend’s apartment in North Hollywood, Calif., according to the Los Angeles Times. Tragically, he was just 32 years old at the time of his passing. Medical reports confirm the actor passed away from an accidental heroin overdose.

Glenn had joined the cast of Roseanne in 1990 during the show’s third season. His character, Mark Healy, was originally meant to be a short-term role. However, he became a central part of the series throughout the remainder of the series, per IMDb. He was later cast for roles on Angel and the Irish soap Fair City.

According to The Irish Independent, Glenn had struggled with addiction in the years following his time on the cast of Roseanne. His co-star Michael Fishman said he never saw signs of drug use during their time on the ABC sitcom, per The Irish Independent, that any struggles “started while working on Angel.” So, his death came as a shock to many of his co-stars who worked beside him on Roseanne.

When Roseanne returned in 2018, the show made the decision not to recast Glenn’s character Mark Healy. TVLine reported at the time that Becky Conner’s husband would not be replaced. Instead, one of Roseanne’s grandchildren was named Mark in his honor. Likewise, the show acknowledged Mark by noting the character died in a motorcycle accident.

Michael Fishman later opened up about the decision on Facebook, “As a show we never considered replacing his character. Recasting as some in the media suggested was never even an option. Glenn is irreplaceable.”

He added as he gushed about how incredible Glenn was to work with: “I have said many times Glenn was an amazing person. He lit up every room he entered and every set he walked on.”

Lecy Goranson, who played Glenn’s on-screen wife Becky, told Access Live that there were moments during filming when the cast felt Glenn's presence.

Beyond his television roles, Glenn had a complicated and tragic family history. Per The Irish Independent, the actor had a biological brother named Ciaran McQuaile Quinn. Sadly, Ciaran was put up for adoption and was unable to meet Glenn before he passed away. While Ciaran was on a quest to find his family, it wasn’t until after Glenn passed away that he learned he had a famous brother.

Glenn's sister, Sonya, shared that Glenn’s family tried to help him with his struggles. Sadly, after a few periods of sobriety, his addiction “consumed him.” Rest in peace, Glenn.