Warren was last seen at approximately 6:30 p.m. on October 2, 1985 in Salt Lake City, Utah. She was leaving the Utah State Employees Credit Union, where she was in management training, at the time. She and a coworker walked across the parking lot to their respective vehicles. Warren never arrived home at her family's residence in Roy, Utah that evening and has not been seen again. She was carrying a Hawaiian keychain with about fifteen keys on it when she went missing.

Warren's car was discovered in the parking lot of the Aladdin Hotel in Las Vegas, Nevada on November 11, 1985, over one month after her initial disappearance. The vehicle appeared to have been parked at the location for some time prior to discovery. There was no trace of Warren at the scene.

Warren's boyfriend at the time of her 1985 disappearance, Cary Hartmann, a former reserve police officer, was later revealed to be a serial rapist and was imprisoned. At his 2005 parole hearing, he stated he was willing to cooperate with authorities regarding Warren's disappearance. Hartmann is still incarcerated and has never been connected to her case.

Douglas Lovell was questioned in Greaves's disappearance in 1993, and in the 1983 disappearance of another Utah woman, Theresa Greaves. Lovell pleaded guilty to the 1985 murder of Joyce Yost, stating he had killed her to keep her from testifying against him in a rape case. Her body was never found. He was sentenced to death, but his guilty plea was overturned on a techicality in 2010 and he will have to face trial again. Lovell maintains his innocence in Greaves and Warren's disappearances and was cooperative with investigators.

Warren left behind a young son, whom her family said she would have never abandoned. Her family had her declared legally deceased in the 1990s, but her case remains open and unsolved.