Father Changes His Story About Killing His Son 17 Years After Wife's Death

When Christina Karlsen perished in a horrific house fire, her death was ruled an accident. But it wasn't until another death in the family 17 years later that police started to look into her husband, Karl Karlsen, as a suspect. Now, for the first time on television, Karl is speaking out about being at the center of the two murder investigations to "Dateline's" Andrea Canning. Andrea talks to Access Hollywood about the case, including what she thought made him "a very interesting accused killer." "Dateline's" "The House on the Hill" airs Feb. 28 at 9/8c on NBC.