Wheeler was last seen entering a red pickup truck outside of Franklin High School in Stockton, California on October 16, 1985. She told friends that she planned to skip classes that day and drive to Valley Springs, California with a male friend. Wheeler has never been heard from again. One of her friends says Wheeler seemed apprehensive about the trip. She asked her friend to tell her father if she didn't return by the time school let out for the day.

Authorities soon learned the identity of her friend: Wesley Howard Shermantine Jr., an acquaintance of Wheeler's family. He was nineteen years old at the time of Wheeler's disappearance. Family members told investigators that Shermantine called their home the morning Wheeler disappeared to confirm their plans for a drive to the mountains. When Shermantine was questioned by authorities shortly after Wheeler vanished, he denied having any involvement in her case. Shermantine also told her family he was innocent. Investigators continued to suspect him, particularly after searching Shermantine's family's cabin in San Andreas, California. Police collected blood and hair evidence at the cabin in 1985, but DNA testing technology prevented the samples from being analyzed until 1999, 14 years after Wheeler disappeared. Investigators privately believed that the blood and hair were hers, but they did not have evidence to support theory at the time.

Shermantine's friend, Loren Joseph Herzog, claimed on videotape that Shermantine bragged about abusing, raping and murdering Wheeler in 1985. Photos of Shermantine and Herzog are posted at the end of this case summary. Herzog and Shermantine were arrested in 1999 for numerous murders in the western United States, including the presumed killings of Wheeler and another missing woman, Cynthia Vanderheiden. Vanderheiden disappeared from California in 1998 after being spotted with both Shermantine and Herzog. Authorities believe that the men lured their victims to their deaths by promising drugs. Both Shermantine and Herzog used methamphetamine in the 1980s and 1990s.

DNA testing proved that the blood and hair samples taken from the San Andreas cabin in 1985 belonged to Wheeler. Shermantine and Herzog have blamed one another for the murders. Shermantine told investigators that Herzog had a key to his cabin in San Andreas and that Herzog was also friends with Wheeler.

Shermantine announced he would reveal the locations of two of the missing victims if authorities gave $20,000 in reward money to his sons. Prosecutors offered to drop the death penalty from Shermantine's sentence if he is convicted of the crimes, but he demanded the reward money instead. The offer was not accepted and Shermantine was convicted of the murders of Wheeler, Vanderheiden and two other individuals in May 2001. Shermantine was sentenced to death for the crimes. He protested the verdict and announced to the courtroom that he was innocent.

Herzog was found guilty of three murders in 2001, but he was spared the death penalty and sentenced to 78 years to life in prison instead. An appelate court tossed out his convictions and Herzog pleaded guilty to a single count of involuntary manslaughter, three counts of being an accessory to a felony, and one drug charge. He was sentenced to 14 years in prison.

In 2010, Herzog was paroled. As per the conditions of his release, he had to keep a curfew, wear an electronic tracking bracelet and live in a trailer on the grounds of High Desert State Prison, although he was free to come and go at will during the daylight hours. In January 2012, he committed suicide by hanging himself inside his trailer. He left a note behind for his family; it didn't reference his crimes. The month before Herzog's death, Shermantine lead the police on an unsuccessful search for Wheeler's body on a hill near his father's former home. Cadaver dogs caught a scent and authorities dug with shovels, pickaxes and a backhoe, but turned up nothing. Shermantine denied having harmed Wheeler and said she'd gone horseback riding with Herzog and died when she fell off the horse.

Investigators are also exploring the possibility that Shermantine may have been involved in the 1997 California disappearances of Hannah Zaccaglini and Karen Knechtel Mero. No charges have been filed against Shermantine in these cases.

Wheeler's parents stayed in their Stockton home for nearly twenty years after her disappearance, hoping she would return. In 2004 they moved to Tennessee. Her remains have never been located.

Left: Shermantine, circa 2000; Center: Herzog, circa 1999; Right: Herzog, circa 2010