Lifetime movies have become a place where nice guys get creepy. Rob Lowe abandoned his pretty boy image to star in “Drew Peterson: Untouchable” as a thuggish cop and suspected — now convicted — killer. Tonight Tom Cavanagh (“Ed”) departs from his gee-shucks persona for the lead role in the TV shocker “Killer Among Us” (7 p.m. Saturday).
At first, he’s Nick Carleton, the nice, married dad of three. But things change dramatically after his wife is murdered, execution-style, outside the family pet store. As we know from “Law & Order” investigations, suspicion immediately falls upon the husband. But months go by without leads.
Meanwhile, things get weird on the domestic front. Nick seems a little too rushed to move on, discarding all of his late wife’s clothes and personal effects. He lavishes expensive gifts on the children, as if to buy their love. Or is it their silence?
In one of many creepy touches, he begins to treat his oldest daughter, high school senior Alex (Tess Atkins), as a kind of surrogate mother/domestic. Only Nick doesn’t know that Alex is also in contact with the impossibly handsome detective Joseph Moran (Boris Kodjoe, “Soul Food”), who harbors doubts about Nick.
‘‘Killer” probably won’t spark a new career for Cavanagh as a scary guy. The rather uneven effort manages to place the spunky, 17-going-on-35 Alex in any number of perilous and uncomfortable situations: replacing her mother with haste while simultaneously spying on her dad and skipping class to have furtive meetings with an older, unmarried cop. “Killer” may begin with a violent murder, but it’s more of a slow, uncomfortable slog toward the inevitable than a heart-pounding thriller.
• A new special, “9/11 Emergency Room” (7 p.m. Saturday, TLC) recalls a tragic day.
Saturday’s other highlights
• NASCAR action (6:30 p.m., ABC), live from Richmond, Va.
• U.S. Open Tennis (7 p.m., CBS) features the Women’s Final.
• UCLA hosts Nebraska in college football (6:30 p.m., Fox).
• “My Cat From Hell” (7 p.m., Animal Planet) offers clips from submitted Internet videos of felines at their worst.
• A single mother (Candace Cameron Bure) adopts a dog, only to learn that a hunky athlete could be the animal’s real owner in the 2012 romance “Puppy Love” (8 p.m., Hallmark).
• A vacation ends in tragedy on “48 Hours Mystery” (9 p.m., CBS).
• A love triangle involving a funeral director ends badly on “Deadly Affairs” (9 p.m., ID), hosted by Susan Lucci.
• Jimmy Fallon hosts “Saturday Night Live” (10:30 p.m., NBC), featuring musical guest Michael Buble.