The Killing of America a 1981 documentary reporting on the decline of the US directed by Sheldon Renan and Leonard Schrader.
Of course one would assume with this being such an old documentary film that it would be out of date and not really relevant in 2018 but it is. While it is true that the United States has never really collapsed since the 80's, well apart from maybe the 2008 financial crash, many of the subjects discussed in the film reflect on problems that are still massive issues in the country. Race tensions, inequality and political blunders are still rife.
In the Killing of America documentary, you will see interviews with members of law enforcement, coroner Thomas Noguchi and convicted serial killers including Sirhan Sirhan.