Details of Disappearance
Yost was last seen in South Ogden, Utah on August 10, 1985. She has never been heard from again. Her car was later found abandoned in the foothills east of town.
Yost disappeared two months after testifying against Douglas Anderson Lovell at his preliminary hearing. She had accused Lovell of kidnapping her in April 1985, taking her to his home in Clearfield, Utah, and raping her. Yost disappeared before his trial, but in December 1985 Lovell was convicted of kidnapping and sexual assault based on her testimony from the preliminary hearing. He was sentenced to two terms of 15 years to life in prison.
A photo of Lovell is posted with this case summary. He was long the prime suspect in Yost's disappearance, and investigators discovered that he'd twice hired friends from prison to murder her between the time of his arrest and the time of the preliminary hearing. (Lovell had met the men while he was serving a previous sentence for an armed robbery conviction. Neither of them actually tried to kill Yost.)
For years investigators lacked the evidence to charge him in her disappearance, until his wife agreed to wear a wire when she went to visit him in prison in 1991 and 1992. Lovell made incriminating statements about Yost's disappearance, saying he could get the death penalty for the crimes he had committed.
In 1993, on the day his murder trial was scheduled to begin, Lovell pleaded guilty to Yost's murder. He stated he broke into Yost's apartment while she was sleeping and threatened her with a knife. She pleaded for her life and promised to drop the sex assault case against him. He then drugged her with Valium, packed a suitcase of her belongings to make it look as if she'd left on her own, took her to a canyon outside of town and strangled her. He said he buried her body in a shallow grave in the Ogden Valley.
Prosecutors agreed not to seek a death sentence against Lovell if he would lead them to Yost's body. He was unable to find the exact spot where he'd buried her, however, in spite of a five-week search. He was sentenced to death in August 1993. He attempted to withdraw his guilty plea weeks later in a letter to the judge, claiming he had not been advised of his constitutional rights.
In September 2010, the Utah Supreme Court overturned his conviction and death sentence on those grounds. In April 2015, Lovell was convicted of murder at trial, sentenced to death again and returned to death row.
Lovell was questioned about his possible involvement in the disappearances of two other Utah women, Sheree Warren
and Theresa Greaves. He maintained his innocence in those cases and cooperated with the investigations. He has not been linked to either of those cases. Greaves's remains were discovered in 2015; her death is under investigation. Warren has never been found.
Yost was declared legally dead in 1992. Foul play is suspected in her case due to the circumstances involved.