Dunn was last seen in Lubbock, Texas on May 31, 1991. He called in sick at work, where he was a car stereo installer, for two days the week he disappeared, then told a co-worker he planned to return to work. He never arrived as expected. When the co-worker went to Dunn's apartment in in the 5800 block of 24th Street in Lubbock on the morning of May 31, no one answered the door.

Dunn's live-in girlfriend, Leisha Hamilton, later told police she'd last seen him early that morning before she left for work. His car and tools were found at his workplace; it would be uncharacteristic of Dunn to leave the items behind, as he was very possessive of them. A large puddle of Dunn's blood was found on the floor inside his apartment, and Luminol testing revealed blood on the walls, ceiling and door of the room. Someone had attempted to clean up, and a patch of carpeting was missing. Hamilton claimed she had not noticed the blood or the missing carpenting, although she continued to live in Dunn's apartment for weeks after his disappearance. Authorities determined that enough blood had been spilled to make it extremely unlikely for Dunn to have survived.

In 1997, Hamilton and a co-defendant, Timothy James Smith, were convicted of Dunn's murder. The prosecution's theory was that the two of them beat Dunn to death inside his apartment and disposed of his body and the carpet in an unknown location. Evidence was introduced that Smith was in love with Hamilton, and believed Dunn was an impediment to their relationship. Investigators believe Hamilton was the primary instigator in the crime and that she was angry because Dunn had become engaged to another woman. Both defendants maintained their innocence at trial. Hamilton, who has a criminal record, was sentenced to 20 years in prison. She came up for parole the first time in 2005. Smith was sentenced to probation.

Dunn's family continues to search for his remains.