December marks the 20th anniversary of the murder of JonBenét Ramsey, a Boulder six-year-old whose sensational killing continues to receive a bevy of national attention (see: the September CBS miniseries The Case Of: JonBenét Ramsey). But hundreds of other local cold-case murders—like these three—have been largely forgotten.

Golden, 1984

Discovered near the Mother Cabrini Shrine on April 7, Mark Groezinger and his 1973 Buick were riddled with bullets. Investigators found enough casings to suggest the killer had reloaded the weapon—a .38-caliber gun—at least twice. Plus, Groezinger’s wallet (with his cash) was inside the vehicle, effectively ruling out a robbery. According to an interview retired Lieutenant John Dunow gave to Unsolved Mysteries, Groezinger’s wife, Judy, became a person of interest when the Jefferson County Sheriff’s Office discovered her version of events from that night didn’t square with witness accounts and that she had recently purchased a .38-caliber pistol from a pawn shop. Judy said her husband had asked her to buy the gun, and she was never charged with the murder.

Lone Tree, 1985

Roger Dean, a local businessman, was murdered in his driveway on November 21. Just before his death, Dean had transferred $32,000 from his company’s bank account to a personal one, leading law enforcement to believe Dean was the target of a blackmail plot. That theory was reinforced when the supposed killer resurfaced: In 1990, a person claiming to be the killer contacted Dean’s widow, Doris, and demanded she pay $100,000 or he would kill her daughter too. Despite some seriously close calls—the extortionist once called Doris from a pay phone at a 7-Eleven in which an unsuspecting investigator was buying coffee—the murderer and blackmailer (if they’re the same person) was never caught.

Denver, 1991

On June 16, a man posing as a bank vice president forced his way into the United Bank of Denver, murdered four guards, and made off with nearly $200,000. Suspecting an inside job, the Denver Police Department zeroed in on retired police sergeant and former bank guard James King, who had shaved his mustache shortly after the heist. Despite a flimsy alibi—he claimed to have been headed to a meeting of a chess club in Capitol Hill that, alas, did not meet in Capitol Hill—no physical evidence tied King to the scene. Even the bank’s head of security testified for the defense, stating that new security measures would have snared a former guard. King was acquitted and, after living the rest of his years in near seclusion, he died in 2013.