David Arthur Preston was 30 when he was last seen on May 10, 1988, in Union City, California. He disappeared under suspicious circumstances and foul play is suspected. At the time he was described as 6 feet 3 inches tall, 175–200 pounds, with blond hair and blue eyes. Distinctive identifiers include an eagle tattoo on his right arm and a vertical scar on his right knee.

Despite investigations, no substantial leads have surfaced and Preston has not been heard from since. His case is listed as endangered missing and his information is entered in databases including NamUs, where efforts to resolve the case remain active. If anyone knew David, saw him in Union City around May 10, 1988, or has information about his tattoos or scar, please come forward.