David Diaz, a 34-year-old Hispanic man from Chicago, was found with multiple gunshot wounds on September 27, 2021, and his death was ruled a homicide. The shooting occurred in a neighborhood described as having high crime rates. The Chicago Police Department opened an investigation and initially questioned several people, but no arrests were reported in the immediate days after the killing.

Police told investigators that Diaz had no known enemies and was not involved in criminal activity, leaving the motive unclear. Detectives faced challenges including a shortage of eyewitnesses and limited physical evidence as they pursued leads. The community responded with vigils and calls for greater efforts to curb violence in the area.