Divorce can be murder. That’s the theme of “Fatal Vows” (9 p.m. Saturday, ID), a new true-crime series devoted to stories about marriages that end in one spouse planning to kill the other. Every story is hosted by Brian Russell, an attorney as well as a forensic and clinical psychologist, and Stacy Kaiser, a licensed psychotherapist and relationship expert.

Our experts explain the motivations that drive some people to murder instead of divorce. The series kicks off with the tale of a “perfect couple,” a Navy commander and his seemingly doting wife. But when she learns that her officer was not a gentleman and had a thing for strip clubs, she files for divorce. This starts a chain of events leading to the grave.

While grim, this series is clearly intended as a Saturday night guilty pleasure. “Fatal” is not the first cable show to cover this territory. Some years back, writer/director John Waters hosted “‘Til Death Do Us Part,” a series on Court TV that had a decidedly tongue-in-cheek take on these deadly doings.

• Lacey Chabert of “Party of Five” fame stars as a star-crossed baker in the cookie-cutter holiday romance “Matchmaker Santa” (7 p.m. Saturday, Hallmark). She’s not the only one cast for her “where are they now?” status. Look for Florence Henderson (“The Brady Bunch”) and John Ratzenberger (“Cheers”).

• Not content to leave the Christmas movie stunt casting to Hallmark, the Lifetime Network counters with the 2012 romance “Holiday High School Reunion” (7 p.m. Saturday), featuring Harry Hamlin (“L.A. Law”) and Marilu Henner (“Taxi”). Rachel Boston (“American Dreams”) stars.

Saturday’s other highlights

• College football games include Oklahoma at West Virginia (6 p.m., Fox); teams TBA (7 p.m., ABC); UTEP at Southern Mississippi (7 p.m., CBS Sports); Kansas State at Baylor (7 p.m., ESPN); Tennessee at Vanderbilt (6 p.m., ESPN 2); Syracuse at Missouri (6 p.m., ESPNU).

• Scheduled on “48 Hours” (9 p.m., CBS): a single highway linked to 20 murder and missing-person cases.

•The gang plays Comic-Con and meets a cult actress on “Wedding Band” (9 p.m., TBS).

• Jeremy Renner hosts “Saturday Night Live” (10:30 p.m., NBC), featuring musical guest Maroon 5.