Cheryl Tiegs will host “Diet America Challenge,”...

Cheryl Tiegs will host “Diet America Challenge,” an hourlong special about dieting that CBS plans to broadcast April 28. Among her guests will be Oprah Winfrey, Charlene Tilton and Los Angeles Dodgers Manager Tommy Lasorda.

ABC plans to devote at least three hours of programming on April 27 to an examination of what it calls “the staggering explosion of violence which is turning our inner-city ghettos into killing grounds.” The network will kick things off with an hourlong report at 10 p.m., hosted by Ted Koppel, then will follow up at 11:30 p.m. with an expanded edition of Koppel’s “Nightline.”

KNBC Channel 4 and the other NBC-owned TV stations have contracted to air a series of four documentary specials, “Raising Good Kids in Bad Times,” dealing with childhood development issues. The shows will be aired quarterly, beginning April 23, and will be hosted by Tom Selleck, Whoopi Goldberg, Michael Landon and Loni Anderson.

“The American Experience,” the historical documentary series that ran on PBS last winter, has received funding for two additional seasons from Aetna Life and Casualty. The first of the new batch of programs will begin airing in October, with subjects to include baseball, the space race, immigrants, Prohibition and 19th-Century feminist Ida B. Wells.

The moon is the setting for “Murder by Moonlight,” a TV movie that will air on CBS May 16. The network describes it as “a romantic science-fiction suspense drama.” Set in the year 2015, it stars Brigitte Nielsen, Julian Sands and Gerald McRaney.

Jane Wyatt will play Patty Duke’s mother in “Amityville: The Evil Escapes,” a TV movie for NBC based on the “Amityville Horror” books. Duke’s character is the one that appears to be under the influence of an evil force, which it then falls to Mom to fight.