Hilbert was last seen in Cincinnati, Ohio on March 13, 1988. He was on spring break from college at Morehead State University in Kentucky. He left a note for his parents, saying he was going to spend a few days with friends at the Ohio State University campus in Columbus. Hilbert never arrived at Ohio State. He had been driving the family car. On April 1, the car was found on a dead-end road, in the Beaver Dam Mountains Wilderness Area. Someone had tried to push the car off a cliff, but it got caught on a tree. The front and rear license plates had been removed and were never found. One of Hilbert's fingerprints was on the passenger side of the car; other fingerprints in the car could not be identified. Inside the vehicle was a book of matches from a Denver, Colorado restaurant and pages from a Long Beach, California phone book. The suitcase of clothes he'd packed to take to Columbus was never located.