Details of Disappearance
Knapp was last seen by his roommate at their residence in University Terrace Apartments at Clemson University in South Carolina on April 11, 1998. His roommate said that Knapp was watching a movie at approximately 10:30 p.m. that evening. Knapp has never been seen again. He was wearing jeans, a t-shirt and sneakers at the time of his disappearance. Knapp may have been wearing a watch. He may have been carrying an expired prescription card, a Keystone Health Plan Central HMO card, an MBNA America Bank card, a Wachovia automatic teller machine (ATM) card and additional bank card at the time of his disappearance.
After several days, Knapp's roommates became concerned because he had not returned to his apartment. They notified his mother, who reported him missing.
Knapp's 1990 white Chevrolet Beretta with Pennsylvania license plates APV9032 was discovered abandoned nine days after he was last seen on April 21, 1998. The vehicle was parked at Table Rock State Park in Pickens, South Carolina, approximately 30 miles from Clemson University, in a very rugged area. Authorities found a receipt from a local Wendy's restaurant dated April 12, 1998 at 1:30 p.m. inside the car. Investigators believe that Knapp drove to the park on April 12, but they are uncertain if he was alone. There was no sign of foul play at the vehicle's location. Authorities searched the surrounding terrain for two weeks and found nothing pertaining to Knapp.
Knapp withdrew $20 from his bank account on the day he disappeared. There as been no activity on the account since then.
Knapp was an ROTC student at Clemson University at the time of his disappearance, studying engineering. He is originally from Pennsylvania, and graduated from Central York High School in 1996. Knapp's mother said that her son was interested in working for a NASCAR racing team in the future. He enjoyed driving cars at fast speeds. Knapp also enjoys mountain bicycling and target shooting. He was previously employed as a restaurant busboy. He had pledged into the Pershing Rifles, an elite military organization, just before his disappearance.
Knapp's mother hired an investigative psychic in March 2002, nearly four years after her son disappeared. The psychic claimed that she saw Knapp's vehicle parked next to an older model red Ford pickup truck in Table Rock State Park on the day he vanished. The psychic also said she saw two girls riding in a convertible car in the park's lot during the same time. The psychic claimed to have visions of Knapp running from an unidentified individual who was apparently chasing him. The psychic saw Knapp run out of breath and collapse on a nearby trail. She claimed that his body was covered by sandy soil. The psychic said that the ground near the park's creek bed matched the soil in her vision. She did not believe that Knapp hiked into the park alone, as some outlets reported. The psychic claimed that Knapp's remains would be located in October or November 2002, but they were not. His case remains unsolved.