Harmon was last seen in Monroe County, Mississippi sometime during July 1985. He has never been heard from again.

James Rodney Mills confessed disposing of Harmon's body in 2009. He is presently incarcerated in Tennessee; in 2001, he pleaded guilty to the 1994 murder of his cousin's husband. Mills's cousin had paid him and an accomplice $25,000 each to shoot her husband. In exchange for his guilty plea, he was spared the death penalty and sentenced to life in prison instead. Mills stated Harmon was killed and he buried his body in someone else's freshly dug grave at a cemetery just 300 yards from Mills's home. Police sent him photos of the cemetery, and he pointed out the spot where he said Harmon's body was buried. When the grave was opened up, however, it contained just one body. Mills has never been charged in Harmon's disappearance, but he maintains his story is true.

Harmon's case remains unsolved.