they've pleaded guilty to killing lydia and seriously injuring her 11-year-old sister zaria who almost died. authorities say kevin and elizabeth shatz beat their children regularly because they believed god wanted them. to the district attorney says the shatz believed -- >> to spare the rod will spoil the child. and if you can train your horse and you can train your dog you can train your children. >> reporter: 7-year-old lydia suffered terribly, supposedly in the name of god. but authorities say this was torture and murder by parents who were supposed to love and cherish their child. inside this house they found important evidence. the so-called biblical rods that shatz had inside. what they were were 15-inch long plumbing supply tubes used to beat the children. and also important, a book was found inside. a book that appeared to light the fuse to the deadly brutality. the book is called "to train up a child." its author is this man on the track, to michael pearl and his wife debbie. they consider themselves observant christians who run an organization called no greater joy ministries

zaria, i'd like to take you to the hospital, okay. >> i probably need to bring a pot cause i'm going to puke. >> at the sentencing hearing the 11-year-old who is still recovering from her serious injuries had the courage to address her parents in open court about her deceased sister. she said why did you adopt her? to kill her? it's a heartbreaking story. kevin pleaded guilty to murder and torture and will be in jail for at least 22 years. elizabeth for at least 12. do you think if the shots did not read the pearl's book, there'd be a good chance that lydia would still be alive. >> i think there would be. >> we reviewed to case to see if there was going to be any blame pointed at us a. so we looked into it. >> when we come back, has the death of little lydia caused the pearls to rethink any of their parenting advice? gary gets a lesson in language. >> i don't use the term hitting. >> what's the word? >> spanking. >> >> a difference? >> absolutely. >> also ahead, gary investigating some disturbing allegations of harsh abuse and brainwashing at a fundamentalist baptist home for so-call

zaria, i'd like to take you to the hospital, okay. >> i probably need to bring a pot cause i'm going to puke. >> at the sentencing hearing the 11-year-old who is still recovering from her serious injuries had the courage to address her parents in open court about her deceased sister. she said why did you adopt her? to kill her? it's a heartbreaking story. kevin pleaded guilty to murder and torture and will be in jail for at least 22 years. elizabeth for at least 12. do you think if the shots did not read the pearl's book, there'd be a good chance that lydia would still be alive. >> i think there would be. >> we reviewed to case to see if there was going to be any blame pointed at us a. so we looked into it. >> when we come back, has the death of little lydia caused the pearls to rethink any of their parenting advice? gary gets a lesson in language. >> i don't use the term hitting. >> what's the word? >> spanking. >> >> a difference? >> absolutely. >> also ahead, gary investigating some disturbing allegations of harsh abuse and brainwashing at a fundamentalist baptist home for so-call