Criminal Minds

Episode 3.10 - Birthright: The team figures out that a serial killer who is kidnapping couples, killing the husbands and holding the wives captive until they misbehave then killing them, is the son of a serial killer (and his wife) from 25 years ago who killed in the same exact way. One of the original killer's victims escaped and had a son from her captor. He and his mother, who was rescued by the original killer's wife, who then killed her husband so he couldn't hurt anyone else, have had a hard life. Source: SpoilerFix.com