The promise of lies, infidelities, and murderous or murdered housewives existing just beneath the surface of the picket fences, manicured lawns, and 2.5 children of suburbia seems too much for television producers to resist. From the daytime soap-opera franchises to “Desperate Housewives,” the networks seem always to be ferreting out the demons lurking around those neatly trimmed bushes.

The HBO film “Mrs. Harris,” which airs Sunday night at 8 p.m., offers an added bonus: It’s all based on a true story.

When Jean Harris killed her longtime lover in 1981, the story quickly swept across the nation and led to a much-publicized trial. Harris was the headmistress of a prestigious girls’ prep school, and her victim – the famous diet doctor Herman Tawnower – was already known for his best-selling book, “The Scarsdale Diet.”The doctor had four gunshot wounds. But Harris claimed it was all a mistake. She had intended the bullets for herself. She just wanted to say goodbye before she went through with it.

Harris maintains her innocence to this day, but her story still captures the public’s imagination. It has only been adapted to film once before, in a 1981 telefilm, “The People vs. Jean Harris,” starring Ellen Burstyn (who puts in a cameo here). The story has all the elements of a film noir, a fact visualized by the montage that runs beneath the opening credits in director Phyllis Nagy’s film for HBO.

From that moment, it is clear that Ms. Nagy is taking a light approach to the material. Starting with the opening death scene, “Mrs. Harris” shoots for a mood reminiscent of “Six Feet Under” – minus the compassion. Like the premiere episode of that series and “American Beauty,” Sam Mendes’s contributions to the suburban horror genre, Ms. Nagy tinges every mundane and ordinary aspect of suburban life with the tension of potential perversity.

The film alternates from the courtroom to the lives of Tarnower (Ben Kingsley) and Harris (Annette Bening), never missing an opportunity to highlight the strangeness of their relationship. From their first sexual encounter to his proposal, their relationship seems a lesson in unnecessary awkwardness.

While the successful doctor proposed to Harris, he soon made it clear that he did not intend to marry her. Harris was forced to adjust to life as a mistress to a man who had many. It doesn’t seem necessary to the filmmakers to fully explain why Ms. Bening’s character puts up with this arrangement. But as she explains to a friend who advises her to leave Tarnower for a man who treats her well: “Cruelty is not a crime. Boring is.”

While the film does not come down conclusively in Harris’s favor, the portrayal is at once sympathetic and opaque. Ms. Bening’s character seems a bit of a proto-feminist – she spurns marriage and decides to raise her sons on her own rather than risk a life of boredom with her husband. She seems to value work force success more than homemaking, but she continues to sport the fashions of the 1960s, and places a disturbing importance on etiquette. Also,she killed the man she was sleeping with.

Not exactly a role model, perhaps, but that hardly seems the point of this film, which is busy showcasing quaint Westchester homes and eccentric characters. It’s less realism than lifestyles of the rich and damaged.

Instead, we are given the opportunity – as in “American Beauty” – to watch Ms. Bening’s delightful screen presence, as she keeps a volatile rage just barely hidden beneath the surface of a fragile exterior. She parades onscreen in various states of aging, while interacting with a cantankerous Mr. Kingsley, and their interplay is well worth everything else. Even if he does get it in the end.

mkeane@nysun.com