Sixty-six-year-old British documentarian Nick Broomfield didn't blend in when he went cruising around South Central Los Angeles to retrace a 22-year serial killing spree. Even with local prostitutes, crack addicts and know-it-alls riding shotgun, the filmmaker and his cameraman stuck out as he worked on his new doc, Tales of the Grim Sleeper — and accused murderer Lonnie Franklin was popular on these streets. In the film, when three neighbors of Franklin's try to chase off Broomfield by hollering “peckerwood,” the director shrugs, “I thought that word was an endearing term,” and promptly crosses the street to say hello.

Faux naiveté is Broomfield's weapon. He wades in deep, then slices himself up as chum. With his gentle, earnest questions, he can charm anyone. (At least, anyone who hasn't been warned by Broomfield's ire-inducing docs Kurt & Courtney and Biggie & Tupac, which made enemies of Courtney Love and Suge Knight, respectively.)

Broomfield also has patience and an eye for the absurd. Watching footage of Franklin entering a courtroom, he notes that the man accused of preying on women is clutching a Nora Roberts paperback romance.

Back on the street, those three men warm up to Broomfield and give the camera good soundbites about their friendship with Franklin, who is now awaiting trial for the murder of at least 10 women.

“He didn't steal cars — he dealt in stolen cars,” one insists. “He dealt in a shitload of stolen cars!” another cackles. While swearing to Franklin's greater innocence, they continue to spend more days with Broomfield until they feel comfortable dishing things they never told the cops. They tell Broomfield about the handcuffs in Franklin's car, the gun he kept in his front pocket, the time he hit a girl in broad daylight. They even hand Broomfield snapshots Franklin took of naked women, some of whom are still missing today. Based on a second box of photos found in Franklin's closet, the police estimate many more women are unaccounted for.

And these aren't the only residents who open up in Broomfield's doc. Some do so by pure happenstance. There's the man who says he rode along as Franklin decided which female drug addicts to abduct, the man who cleaned dark stains out of Franklin's shag van. “When you find bloody clothes in a car, don't you think that's a little odd?” Broomfield asks. “Not really,” the friend replies, and Broomfield lets the absurd moment linger.

There's the babysitter of Chris Franklin, Lonnie's son — she let Dad tie her up with a dog leash. And there's Chris's ex-girlfriend, who found lace panties and sexy Polaroids in the van's glovebox and says Lonnie would listen at the door as she and Chris had sex.

Best of all, there's Pam, an outspoken, newly sober ex-streetwalker who knows everyone in South Central. “I'm a black woman — who gives a fuck about me?” she grumbles. But she's invaluable. Pam identifies some of the girls in Franklin's photos and helps Broomfield track them down, crucial detective work that the police haven't done. She and Broomfield find women who claim to have survived encounters with the Grim Sleeper — at least a half-dozen, none of whom ever spoke to the police.

Why didn't anyone in Tales of the Grim Sleeper tell their story directly to the LAPD? With Franklin already in jail — though, frustratingly, still not on trial after four years in custody — that's the film's main question. Broomfield has two answers: First, no one wanted to risk earning a reputation as a snitch. Second, because the cops never asked. (The LAPD also refused to talk to Broomfield's cameras.)

As recently as the 1990s, LAPD referred to the unsolved murders of addicts and prostitutes as “NHI” — “No Human Involved.” The South Central cops didn't make a public statement about the ongoing killings until an L.A. Weekly exposé forced their hand, telling one activist outright that he's “only killing hookers.” Enietra Margette Washington, the only Grim Sleeper victim the LAPD initially interviewed, described Franklin's rare Pinto to the police and even drove them to the block that Franklin lived on, only to be dismissed as “unreliable.” Washington rolls her eyes: “Every black woman is a hooker, didn't you know?”

A leader from the Black Coalition Fighting Back Serial Murders who pressed for more police involvement in the case admits that actually calling the cops is futile. “You cannot just as a black person walk into an LAPD, LASD station and say, 'I have something to report,' ” the activist sighs. “It is a 99 percent chance that it is going to be an unpleasant situation for you.”

Broomfield isn't as scared. When he's pulled over by the LAPD for driving without a seatbelt, he cheerfully uses the opportunity to ask the cops what they know about the case — an ultimate, if inadvertent, moment of white privilege.

Still, the documentary whispers what Broomfield doesn't dare say outright: that the cops might have sympathized with the Grim Sleeper's urge to get crack whores off the streets.

“This is not just a story about Lonnie but about a people in one of the world's most prosperous cities that have been left behind,” Broomfield cautions. But while Tales of the Grim Sleeper is a South Central story, the cloud it stirs up looms larger than Los Angeles, shadowing Ferguson, Missouri, and beyond.

Warns Pam, “Just because they have Lonnie doesn't mean this is over.”

TALES OF THE GRIM SLEEPER | Directed by Nick Broomfield | HBO Documentary Films | Playhouse