Ace is the nephew of Reginald 'Pop' Merrill. He leads a teenage gang of bullies who torment and terrorize Gordie LaChance, Chris Chambers, Teddy Duchamp and Vern Tessio. His closest friends among his gang are Norman "Fuzzy' Bracowicz and Richard "Eyeball" Chambers, Chris's older brother. He once had a girlfriend named Betsy Malenfant.
After being caught by Sheriff Alan Pangborn in the early-to-mid-80s for breaking and entering, Ace was sent to Shawshank Penitentiary for 4 years. After being released, Ace eventually made his way back to Castle Rock. He died there in 1991.
John Merrill will be played by Paul Sparks in Season Two of Castle Rock. He will be taking over his uncle Reginald's criminal business and threatening the fragile peace between Castle Rock, Maine and Jerusalem's Lot, Maine.
- "We're gonna get you for this."
- "You're dead."
- "What are you gonna do, shoot us all?"
- "This is big time, baby."
- "C'mon kid, you ain't got the sack to shoot a woodchuck."