Before he won his Oscar, before he starting studying infamous murder cases, before taking on Robert McNamara and the whole justification for the Vietnam War, documentary filmmaker Errol Morris was known for finding America’s most colorful eccentrics and putting their eccentricity on film.

From his debut films, “Gates of Heaven” and “Vernon, Florida” through “Mr. Death,” Morris could be counted on to find all manner of rubes, obsessives and cranks, people who would tell their stories to the camera and let us appreciate both their humanity and how funny they were.

“Tabloid” is something of a throwback film, a bizarre crime tale recounted by the loopy ex-beauty queen alleged to have committed it. And in Joyce McKinney, Morris has found a fittingly weird and funny muse.

McKinney was somewhat spoiled rural Carolina girl transplanted to the Mormon mountain west. She wanted for little, became Miss Wyoming and then set her sights on this plump but earnest Mormon fellow her own age. But when Kirk, her intended, “vanished,” sent off to Britain to do mission work to perhaps keep him away from Joyce, the beauty queen didn’t take it lying down. She got together the cash, hired a bodyguard and a pilot and plotted a way to “liberate” her fiance, “to get him out of this cult.”

Since this entailed flying to London, grabbing Kirk and tying him up for a weekend of corrupting, converting sex, the Latter Day Saints there called the cops. Next thing you know, “those crazy newspapers” had labeled Joyce “the beauty queen” who had “manacled a Mormon” to save him.

Morris invented this gadget, years ago, that allows him to look his subjects straight in the eye when he’s interviewing them, causing them to answer directly and sincerely, to the camera. He usually lets them tell their stories, uninterrupted. But here, his chortles, snorts and incredulous questions off camera suggest a guy who is sympathetic to every version of this tale that each person telling it gives him.

Thus, he indulges Joyce’s blunt, narrow-minded shots at Mormonism — “They made me think they were a CHURCH!” — her outright mockery of “Temple garments” (“Magical underwear”). He even uses a former Mormon missionary to buttress her accusations of the weirdness of this recent offspring of mainstream Christianity.

And Morris encourages a bemused former co-conspirator and a couple of tabloid veterans who remember this late 1970s scandal to have a laugh at Joyce’s expense — at her obsessive behavior, her “acting” ability, the fun she seemed to have both in court and on the run from the law (silly but functional disguises).

“It was a perfect tabloid story,” the Brit Peter Tory, who covered it, remembers.  “Kinky sex, religion, kidnapping, a beauty queen.”

It’s a film shot and edited in a tabloid-mimicking style, with big headlines, sexy photos, ironic cartoons and sarcastic stock footage of 1970s fashions, Mormon values and the like.  And at its center is the riveting, riotously funny and yet seemingly sincere Joyce — plainly a bit delusional, plainly given to living her own lie about what really happened back then, but just as plainly a woman with enough credibility to make you wonder if her version of events isn’t closer to the truth than the one that hit the tabloids.

Well, maybe just a teensy tiny bit closer.

MPAA RAting: unrated, with nudity, adult sexual themes, profanity

Cast: Joyce McKinney, Kent Gavin, Peter Tory

Credits: Directed by Errol Morris, produced by Julie Bilson Ahlberg and Mark Lipson. A Sundance Selects release. Running time: 1:27