Thin blue line

Proponents say that the idea behind the various graphics that incorporate a thin blue line is that law enforcement is a Thin Blue Line that stands between chaos and order or between criminals and the potential victims of crime, and it is primarily used to show solidarity with police. Opponents note that the representations of the public and the criminals as black bars on either side of the blue line are identical, and suggest that the symbology represents a police vs. everyone else mindset.

Use of the term became especially widespread following the release of Errol Morris' 1988 documentary film The Thin Blue Line, about the murder of a Dallas Police officer Robert W Wood. Judge Don Metcalfe, who presided over the trial of Randall Adams, states in the film that prosecutor "Doug Mulder's final argument was one I'd never heard before: about the 'thin blue line' of police that separate the public from anarchy." The judge admitted to being deeply moved by the prosecutor's words, though the trial resulted in a wrongful conviction and death sentence.