After his wife Kathleen’s suspicious death in December 2001, writer Michael Peterson became the prime suspect in what police believe was a bludgeoning murder. Peterson claims Kathleen fell to her death on a staircase, but it seems mighty coincidental in light of the fact a close family friend — whose children the Petersons raised — died in an identical accident 18 years earlier. Primetime Thursday picks up the case from the first call to police to the final verdict in court during two-hour documentary The Stair Case, on ABC Ch. 7 at 8 p.m.

 In another spousal murder, Wisconsin high school teacher Diane Borchardt maintains her innocence in the 1994 murder of her cheating husband, sitting for an interview on American Justice almost a decade after she was convicted for hiring three teens to gun him down, on A&E Ch. 20 at 8 p.m. and midnight.

 Tru fears she’s lost her uncanny ability to turn back time just when she’s got her hands full with two corpses who want to rejoin the living on Tru Calling, on Fox Ch. 49 at 8 p.m.

 The CSIs are in the middle of a law enforcement relay race in the desert when they stumble on to dead cop — one of three officers who die suddenly during the meet — on CSI: Crime Scene Investigation, on CBS Ch. 4 at 8 p.m.

 Ketchup heiress Teresa Heinz Kerry and Elizabeth Edwards are among the political spouses who share personal tidbits about life in a campaign fishbowl during two-hour A&E special Washington Wives, on Ch. 20 at 9 p.m. and 1 a.m.

 The doctors are in on NBC. A four-episode Scrubs mini-marathon has Dr. Cox reminding the young doctors that he’s still the boss, on Ch. 6 at 7 p.m. and forcing his brother-in-law (Brendan Fraser) to have a checkup at 8 p.m. The final two episodes feature Turk and Carla’s rehearsal dinner and wedding.

 Dr. Weaver is forced to give up her baby son to her lover’s family and Dr. Kovac feels like a third wheel when Sam’s ex-husband makes a comeback on ER, on NBC Ch. 6 at 9 p.m.

 Katharine Hepburn tries to have niece Elizabeth Taylor lobotomized to prevent her from spilling a sordid family secret in 1959 drama Suddenly Last Summer, on Vision Ch. 51 at 7 p.m.