Dateline NBC: Season 2025, Episode 11

2025 - 11: Deadly Obsession

Kansas couple Mike Sisco and Karen Harkness are found dead by their parents before a family fish fry in 2002. A years-long search for evidence and three criminal trials over two decades reveal strained dynamics within one victim's family.INTERVIEWS WITH: Mike Sisco's mother Carol Sisco, daughter Hailey Seel, sister Cathy Boots and brother-in-law Mark Boots; Karen Harkness' daughter Erin Harkness Sutton and son Chad Harkness; Fmr. Topeka police Sgt. Richard Volle; Shawnee County District Attorney Mike Kagay; and others.