On Oct. 20, 1969, then-Riverside Police Chief Lambert “Curly” Kinkead sent a letter to Napa County Sheriff Earl Randol saying that the murder of Cheri Jo Bates followed a “similar M.O. of your ‘Zodiac’” suspect (per Fox News). The letter was uncovered by a group of private investigators who call themselves the Case Breakers. Despite the fact that they claim to have nailed down the exact identity of the Zodiac killer (a man named Gary Francis Poste), authorities are skeptical of their findings (per Independent).

Bates’s body was discovered in an alleyway on the campus of Riverside City College. She’d been stabbed multiple times in the chest and back and her throat had been cut. She’d also been beaten and choked. 

Kinkead’s letter explained that upon leaving the library, Bates tried to start her car, but it had been tampered with and wouldn’t run. On her way to find assistance, she’d presumably been abducted and left for dead by an unknown suspect. Kinkead stated that his department received a letter from someone confessing to Bates’ murder with details only the killer would know. He remarked that the mysterious letter had numerous misspellings and punctuation errors that mirrored those contained in letters written by the Zodiac Killer (via Fox News). Nonetheless, the link between Cheri Jo Bates and the Zodiac Killer has not been confirmed, and the identity of the murderer remains an obscure mystery to this day.