Sheree Warren

Sheree Warren was a 25-year-old employee of the Utah State Employees Credit Union, living in Roy, Utah, and raising a three-year-old son while going through a divorce from her husband, Charles Warren. On the evening of October 2, 1985, she left the credit union's offices in Salt Lake City at about 6:30 p.m., telling a coworker she was headed to a nearby Toyota dealership to meet her estranged husband and give him a ride back to Ogden. She was never confirmed to have arrived at the dealership. When Warren and her son failed to return home, her mother, who had been watching the boy, reported her missing the next day.

Suspicion of foul play deepened on November 11, 1985, when Warren's maroon 1984 Toyota Corolla was found abandoned in the parking lot of the Aladdin hotel-casino in Las Vegas, more than 400 miles away. Detectives did not believe Warren had driven it there herself. Investigators focused on two men in her life. Charles Warren told police he had called off the planned meeting and gone jogging in downtown Ogden, an account police could not verify; according to the Charley Project, he and his first wife, who partially supported his alibi, both later refused polygraph examinations. He died in 2022 without ever being charged. Warren's boyfriend, Cary Hartmann, a former Ogden Police Department reserve officer, said he had spent the evening at an Ogden bar.

Hartmann's background later drew renewed scrutiny: in the years after Warren vanished he was convicted of multiple rapes in the Ogden area and spent decades in prison before being released in March 2020. He has never been charged in connection with Warren's disappearance. An elk hunting guide reported encountering Hartmann trespassing near Causey Reservoir, in the mountains east of Ogden, on October 6, 1985 — four days after Warren was last seen — though when detectives questioned him in 2005, Hartmann denied having been in the area. KSL's 'Cold' podcast, which devoted its third season to the case, reported additional inconsistencies: Hartmann's Weber State College timecard showed he took eight hours off work on October 3, 1985, contradicting his earlier statement that he had worked that day, and a period airline timetable showed a person could have driven Warren's car to Las Vegas overnight and returned to Salt Lake City on an early-morning flight. Both observations concern opportunity only; neither man was ever charged, and both maintained their innocence.

Warren's family, who said she never would have abandoned her young son, had her declared legally deceased in the 1990s. The case has remained active: in August 2023, Roy City police excavated a suspected gravesite in the mountains near Causey Reservoir after receiving information in the case, but found nothing. Police presume Warren was murdered, though her remains have never been located. The investigation is now handled by the Weber Metro Cold Case Task Force together with the Roy Police Department, and authorities continue to seek tips from the public.