Serial killers are fascinating; their acts are repulsive but you can't help wonder what makes them tick. Yet what's marvelous about "Appropriate Adult" (10 tonight, Sundance Channel) isn't that it lets you into the mind of a serial killer. Instead, what's revealed in the film is the perilous vulnerability of that attraction to them.

"Adult" is the true story of Brits Fred West (Dominic West) and his wife Rose (Monica Dolan) who murdered about a dozen women, including two of their children, over a decade. When the film opens, Fred West has been under suspicion for a while, so when the police bring him in this time, after his daughter disappears, they request an 'appropriate adult,' a person who sits in with vulnerable suspects during police interviews to look after their interest.
 

Adam Leroy Lane, the North Carolina serial killer who randomly murdered women across the northeastern United States, is the subject of tonight's '48 Hours: Live to Tell.'

Actually, to be more precise, the Massachusetts teenager, who along with her family finally stopped Lane's killing spree, is really the star of the show.

In July 2007, 15-year-old Shea McDonough (left) was attacked in her Chelmsford, Mass., home in the middle of the night while her parents slept just down the hall. Awakened by the sound of Shea whimpering, her parents investigated and found the masked trucker from Jonesville attacking their daughter with a knife. Her parents bravely fought the much larger Lane while Shea called 911.