Henry A. Mateo was 19 when he was fatally stabbed on August 22, 2009, on a street in the Mission Hill neighborhood of Boston. The incident happened at 16 Horadan Way, and Boston Police officers responded to a call reporting a person stabbed. The Office of the Chief Medical Examiner ruled the death a homicide.

No arrests have been announced and no suspects have been publicly identified; the investigation remains open. For family and friends, the loss is compounded by the absence of accountability and the case’s unresolved status.

If anyone knew Henry, was in Mission Hill on August 22, 2009, or has information that could help, please come forward.