Tales of the Grim Sleeper is not a sick pun but refers to a sicko serial killer pretty much ignored for a quarter century by police and media and today still not to face trial until at least five years after his apprehension by pure accident. The record total of his victims will never be known but may reach a hundred and seventy-five more than that of Jack the Ripper’s “canonical five” London Whitechapel tarts. But because the Grim Sleeper’s ‘ho’s were Los Angeles South Central blacks with many of them addicts, few in the celebrity town, nation and world took notice.

About slum clearance, Nick Broomfield’s first, 1970 film title, Who Cares, says it all. Often in tandem with life and cinema partner Joan Churchill, the American-based Brit has built his solid reputation treating social aberration in lesbian serial killings, music-icon antics and suicides, and high-end glitterati prostitution, documenting as an observer while yet openly placing himself within the frame.

Working here with cinematographer son Barney, he opens with the 2010 arrest of Lonnie David Franklin, Jr., so helpful and popular a member of his neighborhood that unbelieving homeboys across the street verbally assault the film crew of two. But through openness and a non-American accent, the director became the friend and confidant of these “Three Stooges” who reveal details that alter their own perceptions and shed light into hidden darkness.

Late in the hour and three-quarters, LAPD and city officials pat themselves on the back for “diligent” detective work in what, unmentioned, had been for them just another ignorable NHI, No Human Involved, case of low-to-zero priority concerning marginalized citizens or illegals. The handful of women like Anitria Washington who escaped the killer’s van and house would be deemed “unreliable” and in any case would not dream of voluntarily reporting anything to the Man. So, with no official warning to the public of the series of disappearances and deaths, this African-American area of joblessness, hopelessness and addiction was never put on its guard.

Concerned women are interviewed, those who for decades organized, publicized and fought as the Black Coalition Fighting Back Serial Murders. By far most of all, we meet “subject” Pamela Brooks, the delightful ex-street woman who introduced and guided these “English friends” to and through people and places otherwise closed and potentially dangerous to them. Film-credited as South Central Guide & Co-ordinator, she was very much there onstage with the Broomfields for the New York Film Festival press and media screening and Q&A.

The State of California has the nation’s highest percentage of sex offenders, which the director linked to “institutional misogyny.” To him, nonetheless, the documentary’s overriding theme is the destruction of a community through governmental neglect and indifference, allowing crack cocaine and other substance abuses to take over with resultant fatherless families, fear, addiction, prostitution, gangs, crime and killings.

Only Pam received compensation, as well she should, with many participants “basically coming up to the car” or telephoning on their own if not contacted through referrals and actively searched out. There was no working script “to make things happen.” “Letting the situation develop and speak for itself,” they lucked onto Pam early on, the rest occurring “spontaneously, it couldn’t have been shot,” insisted Barney, “any other way.”

In a prisoner’s orange jump suit, soft- and well-spoken Franklin is innocent until proved guilty. He has not made it into Psycho U.S.A.: Famous American Killers You Never Heard Of.

Proudly sober six years now, Pam points out that, whatever their standing in the eyes of the larger society, these presumably dead women are human beings, a whole poster board of head shots of smiles and truncated hopes. That such a fact needs to be verbalized indicates what they are up against, in a deteriorated disregarded community where no one has any idea of the number of homicides.

(Released by HBO Documentary Films; not rated by MPAA.)