Stephen Root told AP News at the BAFTA TV Tea Party at The Maybourne Beverly Hills on September 14 that he voices Brian Heder in GTA 6, becoming the first actor in the game's cast to confirm their role publicly. Rockstar Games has not made any official casting announcement.
Root told AP News that his resemblance to Heder had already become an open secret. "I think from the first rollout of GTA that they were doing maybe almost a year ago, they had my character in there, and there are too many people who knew me from King of the Hill and my voice! So I think that secret kind of got divulged then," he said. "I'm so happy to be involved with it," he added. "It's an amazing thing to look at."
Root is known for playing Bill Dauterive and Buck Strickland in King of the Hill and is nominated this Emmy season for Outstanding Supporting Actor in a Comedy Series for his work in Widow's Bay on Apple TV+. The BAFTA TV Tea Party is a traditional Emmy-weekend event. Rockstar describes Brian Heder as "a classic drug runner from the golden age of smuggling in the Keys." He runs Brian's Boat Works & Marina in the Leonida Keys and lets protagonist Jason Duval live rent-free on his property in exchange for help with local shakedowns.