Harper was last seen at her apartment in Grand Ridge, Arkansas near Little Rock, off of Jacksonville Cato Road, on March 4, 1986. A neighbor went to visit her that day and left at approximately 9:30 p.m. The same neighbor heard noises from Harper's residence between approximately 11:00 and 11:30 p.m. that evening, but did not investigate the sounds. They were not very loud or threatening.

Harper did not arrive at work the following morning as scheduled and a co-worker checked her apartment and found her two-year-old daughter alone and blood on the apartment's front door. There was no sign of Harper and she has never been heard from again. Her car was found abandoned in a commuter parking lot near Crystal Hill, nine miles away from her home, shortly after her disappearance. There was an unidentified set of fingerprints inside the vehicle.

Harper worked for the Internal Revenue Service (IRS) at the time of her disappearance. She had finalized her divorce just four months prior to vanishing. In 1990, investigators searched the backyard of Harper's ex-husband's house, where she had lived prior to the divorce. They found a bone fragment but couldn't match it to Harper. Her case remains unsolved.

Police and Harper's loved ones suspect foul play in her disappearance. She is described as a devoted mother who would not have willingly abandoned her child. There is very little evidence available in her case, however.