David William Siino was 31 when he died in San Diego, California, on November 19, 1988. Authorities concluded his death was not natural and the circumstances pointed toward foul play, prompting a San Diego Police Department homicide inquiry.

Detectives interviewed witnesses and analyzed forensic evidence, and over the years several suspects were considered but none were conclusively linked to the crime. The investigation has been periodically revisited and evidence has been re-examined as forensic technology advanced, but the case remains unsolved.

Anyone with information about David Siino or events in San Diego around November 19, 1988, is asked to come forward.