David Mark Schwarzschild was 21 when he was last seen in San Francisco on August 2, 1979. He stood about 5 feet 9 inches to 5 feet 10 inches and weighed around 160 pounds, with brown hair and hazel eyes. At the time he may have used the aliases David Black or Mark Black.

Very few details about the circumstances of his disappearance have surfaced. The case is listed with the San Francisco Police Department and NamUs, and no significant leads or confirmed developments have been reported. His family continues to hope for answers.

If anyone knew David, saw him around August 2, 1979, or has information about the names David Black or Mark Black used in San Francisco, please share what you know.