Details of Disappearance
Horn was last seen on March 7, 1986, when he left his residence in Santa Ana, California to drive to northern California for a business trip. He planned to visit his daughter in Oregon afterwards, but he later told his daughter he'd changed his mind and would be going directly home instead. He has never been heard from again. His family reported him missing on March 13.
On April 7, a month after Horn disappeared, his car was found abandoned in Houston, Texas. The passenger seat headrest was soaked in blood, which DNA testing provded was Horn's.
Steven Wayne White, a business associate of Horn's, tried to cash a $60,000 check drawn on Horn's account after his disappearance. He was considered a person of interest in his disappearance from early in the investigation, but for decades police lacked the evidence to charge him.
A photo of White is posted with this case summary. In June 1987, he and his girlfriend were arrested for the murder of James Boyd, who disappeared from Florida in February of that year. White's girlfriend ultimately pleaded guilty to theft and returned to her native France; White was convicted of murder and sentenced to 25 years to life in prison.
In June 2015, he was charged with Horn's murder as well. When interviewed by police, he confessed to the crime. In October 2017, White pleaded guilty to second-degree murder in Horn's case.
Horn was a retired dentist in 1986. His body, like Boyd's, has never been found. Foul play is suspected in both disappearances due to the circumstances involved.