The outstanding cable movie “An American Crime” (8 p.m., today, Showtime) looks back at a forgotten event from 1965 once considered the most horrible in the history of Indiana.

Ellen Page (“Juno”) stars as Sylvia Likens, a pretty, well-mannered, devout teen whose parents’ itinerant jobs take them away for months at a time. They place Sylvia and her lame sister in the care of a stranger, Gertrude Baniszewski (Catherine Keener, “Capote”), a beleaguered, divorced mother of seven who does ironing and odd jobs to pay the rent on her ramshackle house on the poor side of the tracks.

Sylvia finds herself on the wrong side of Gertrude, a woman brought masterfully and horribly to life by Keener in a haunting performance.

¢ Prime time salutes mothers real, imagined and animated on Mother’s Day. Glenn Close returns to the “The Simpsons” (7 p.m., Sunday, Fox) as the voice of Homer’s often-absent mother.

On “Everybody Hates Chris” (7 p.m., Sunday, CW), Chris economizes on his Mother’s Day gift only to discover that the bootleg perfume gives Rochelle a rash.

Indefatigable TV fixtures Donny and Marie Osmond host something called “America’s Favorite Mom” (6 p.m., Sunday, NBC), a contest between five finalists selected by an online vote.

¢ Fans of “Extreme Makeover: Home Edition” (7 p.m., Sunday, ABC) are in luck. Right after the charitable-construction work on “Makeover,” they can tune to “Hollywood Habitat for Humanity” (8 p.m., Sunday, DIY), featuring a Los Angeles build-a-thon with stars, including Garth Brooks.

¢ F. Murray Abraham narrates “Prince of the Alps,” a “Nature” (7 p.m., Sunday, PBS) tale of a red deer calf’s struggle to survive the harsh winters of the Austrian alps and the intrusion of civilization on his lonely world.

In other nature news, “Caught on Safari: Battle at Kruger” (8 p.m., Sunday, National Geographic) re-examines an amateur video that has become an Internet sensation. More than 25 million viewers have watched “Kruger,” a once-in-a-lifetime glimpse at a pride of lions stealing a baby water buffalo, only to have the giant jungle cats set upon by crocodiles and then besieged by the angered herd of buffalo who surround and scatter the lions with a canny strategy reminiscent of military warfare.

Today’s highlights

¢ NASCAR action (6 p.m., Fox).

¢ NBA Conference Semifinals (7 p.m., ABC).

¢ Christiane Amanpour covers the visit of the New York Philharmonic Orchestra to one of the world’s most dangerous and paranoid nations on “Notes from North Korea” (7 p.m., CNN).

¢ Spanish conquistadors discover an Aztec tribe offering sacrifices to a dinosaur in the 2008 shocker “Aztec Rex” (8 p.m., Sci Fi).

¢ Scheduled on “48 Hours Mystery” (9 p.m., CBS): Doubts grow about the death of a minister’s wife.

¢ Shia LaBeouf hosts “Saturday Night Live” (10:30 p.m., NBC), featuring musical guest My Morning Jacket.

Sunday’s highlights

¢ Scheduled on “60 Minutes” (6 p.m., CBS): Chiquita Brands; immigration and Alec Baldwin.

¢ A winner emerges on a two-hour “Survivor” (7 p.m., CBS), followed by a reunion (9 p.m.).

¢ Sarah uncovers another one of her father’s grim secrets on the second-season finale of “Brothers & Sisters” (9 p.m., ABC).