David M. Allen, 54, was killed in San Francisco on November 30, 2013. The scarcity of public detail leaves key questions about how and why he was killed unanswered.

Allen’s death is one of the homicides that year in San Francisco and underscores the difficulty of achieving closure when basic facts remain unavailable. If anyone knew David, saw him on or around November 30, 2013, or has information that could help investigators, please come forward to assist the inquiry.