Even the most skillful actors occasionally find themselves saddled with roles they can’t make sense of. This is Catherine Keener’s misfortune in “An American Crime,” a dramatization of a horrific act of communal sadism that took place in Indiana in 1965, culminating with the death of a teenage girl.

As Gertrude Baniszewski, the chain-smoking, drug-addicted single mother of seven who acted as the ringleader, Ms. Keener does her best to humanize a woman who behaved monstrously without losing sight of the monstrosity, but it’s an uphill climb. Neither the script nor the interpretation quite adds up. But then, as demonstrated by clunky courtroom scenes featuring verbatim transcripts from the trial (Bradley Whitford plays the prosecutor), nobody could make sense of this horror show in real life, either.

Set less than two years before the Summer of Love, “An American Crime,” which airs Saturday at 10 p.m. on Showtime, evokes an America that feels closer to the 1950s than the decade that crackled with rock music, protest, and war. Instead, there’s church and children — six girls and a boy — and a single mother trying desperately to cope as she swigs cough medicine (for her “asthma”), hoards every dollar (kept in a drawer), and, though on the cusp of middle age, continually falls prey to worthless men who flatter her sexual vanity. The latest entrant is a feckless James Dean look-alike (James Franco), 15 years her junior, and he’s left a baby behind as a calling card.

It’s an unexpected source of income — $20 a week — that changes Gertrude’s life. That’s the monetary compensation offered by two traveling circus workers if she’ll board their two teenage daughters while they’re on the road. The girls, 16-year-old Sylvia Likens (Ellen Page) and 14-year-old Jenny (Hayley McFarland) are normal, sweet-tempered, and well-behaved. Jennie had polio and Sylvia is a bit of a flirt, but they fit easily into the chaotic household. Ms. Page, who has already made a name for herself in such films as “Hard Candy” and “Juno,” is particularly adept at portraying a teenage combination of innocence and sexual awakening.

So what goes wrong? Well, 17-year-old Paula (Ari Graynor), Gertrude’s oldest daughter, is made pregnant by a married man. Paula tells Sylvia, who has become a confidante, and word accidentally leaks out. Paula’s name is sullied, but she denies the pregnancy to her mother. Thus Sylvia is blamed for “spreading lies,” and Gertrude the disciplinarian emerges, more or less out of nowhere, brandishing a belt. Sylvia is sent down to the basement for “punishment,” where she will have to pay for Gertrude’s years of frustration, anger, and confused emotions about her own sexual past.

Punishment is soon superseded by outright torture (whippings, brandings, cigarette burns), with a houseful of children joining in. Sylvia is locked permanently in the basement, and dropping by to torment her becomes a sick source of thrills for the children in the vicinity. The neighbors hear strange cries; suspicion about what exactly is going on in the Baniszewski household is widespread. But, mysteriously, no one does or says anything. Sylvia herself displays a peculiar propensity for martyrdom, not that she has much choice, and eventually she dies.

The subject of “An American Crime” is, of course, evil — a word subjected to a debilitating workout since September 11, 2001, with the result that it now lies limp and depleted, even shunned, in a ditch somewhere to the side of polite conversation. Had the occupation of Iraq been a swift and lasting success, “evil” would be strutting its stuff and doing extremely well at dinner parties. Instead, it’s been more or less shamed into silence, except when it is attached to American actions. Is the communal nature of the crime supposed to remind us of Abu Ghraib?

Hence, perhaps, the film’s title, which strains at significance (there is nothing particularly “American” about the actions depicted), along with Showtime’s odd claim that Sylvia was brutalized for the crime of being “different.” If there was anything “different” about Sylvia, it’s simply that she was nicer than most people.

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In “Notes From North Korea,” a new documentary from CNN’s “Special Investigations Unit” airing this Saturday and Sunday, evil — as in, “Axis of …” — is alternately acknowledged and questioned. An account of the New York Philharmonic’s recent visit to the land of Kim Jong-Il (otherwise known as the “Dear Leader”), the film is a welcome peek into a country which, for millions, is effectively one enormous, inescapable basement.

The program is presented by Christiane Amanpour, and one has to commend her for actually venturing out and bringing us this sort of stuff. The sight of a gorgeous, balletic, baton-wielding female traffic cop in Pyongyang is something I won’t soon forget, even if there’s hardly any traffic and she was there just for show. As Ms. Amanpour states, the North Korean capital is arguably entirely for show — “a Potemkin city” — and the lights switched on for the Philharmonic’s visit were extinguished as soon as it left. She doesn’t ignore the mass starvation suffered by the population, however, and she interviews a South Korean member of the Philharmonic who considered boycotting the trip, as well as an American official who is critical of it.

On the other hand, Ms. Amanpour can be willfully unfair. Talking to a young Korean woman, she brings up President Bush’s “Axis of Evil” speech in a manner that suggests Mr. Bush was referring to people like her, as opposed to the psychopath running the place. Couple this with the controversial remarks (unmentioned in the film) made by the Philharmonic’s conductor, Lorin Maazel, to the effect that America’s human rights record puts us in a dubious position to judge “the errors” made by others, and you have to wonder if this orchestral visitation could have accomplished anything of true value. America commits crimes, totalitarian regimes are merely guilty of “errors” and, in her summation, Ms. Amanpour prattles on about “these sworn enemies” as if both parties were equally foreign to her and both were on an equal moral footing. It’s all slightly nauseating.

bbernhard@nysun.com