A Californian couple accused of beating their 7-year-old adopted daughter to death have appeared in court at a preliminary hearing.

Kevin and Elizabeth Schatz face one count of murder, one count of torture and one count of child abuse. The torture count alleges that the parents beat their 11-year-old adopted daughter so severely she ended up in the hospital with kidney failure. The child abuse charge is for bruising authorities reportedly found on the couple's 10-year-old biological son.

Seven-year-old adopted daughter Lydia died of blunt force trauma in February. According to authorities, she was beaten for several hours with a quarter-inch plumbing supply line as her parents took turns holding her down and using the instrument. The blows reportedly cause Rhabdomyolysis, which is a breakdown of muscle tissue which fatally damaged her vital organs. The 11-year-old was allegedly beaten in a similar manner the previous night.

According to Butte County District Attorney Mike Ramsey, the parents appeared to be following the methods of Michael and Debi Pearl, founders of a controversial fundamentalist religious group, No Greater Joy Ministries.

They also wrote a controversial parenting book To Train Up a Child. In their literature, the Pearls encourage parents to use a quarter-inch plumbing supply line (or other items like rulers, paddles Advertisement or tree branches) as a rod to train up their children. Though they tell parents not to injure their children, they also encourage constant switching or licks for not only disobedience but also for things like spilling nuts or being foolish. Additional licks are recommended when the child cries out.

Kevin and Elizabeth Schatz, the California couple who were arrested in February 2010 in the beating death of one child and the severe beating of another, have been sentenced to prison.

Authorities said the couple used a quarter-inch plumber's supply line during a biblical chastisement that went too far, resulting in medical complications that caused the death Feb. 5 of 7-year-old Lydia Schatz and left her sister, Zariah, 11, hospitalized with serious injuries.

Kevin Schatz was sentenced to two life terms for second-degree murder and torture and will have to serve at 22 years. Elizabeth Schatz was sentenced to 13 years, four months for voluntary manslaughter and infliction of unlawful corporal punishment.

What the police found when they searched the Paradise home ... sheds some light on the Schatzes' private lives, and their adherence to Christian fundamentalist ideals, in particular the writings of one well-known couple. Police found, on the Schatzes' bed, a 15-inch section of PVC tube, a quarter-inch thick. They believe it to be the murder weapon, as both Lydia and Zariah had whip-like marks that matched the length and width of the pipe. It lay beside a children's book.

The PVC tube may seem like a strange punishment tool, but for those familiar with the teachings of Christian fundamentalists and authors Michael and Debi Pearl, it is nothing new.

On the Pearls' Web page, nogreaterjoy.org, Michael Pearl writes about training children in two sections titled In Defense of Biblical Chastisement, parts one and two: As a rule, do not use your hand. Hands are for loving and helping. If an adult swings his or her hand fast enough to cause pain to the surface of the skin, there is a danger of damaging bones and joints. The most painful nerves are just under the surface of the skin. A swift swat with a light, flexible instrument will sting without bruising or causing internal damage. Many people are using a section of 1/4 inch plumber's supply line as a spanking instrument. It will fit in your purse or hang around your neck. You can buy them for under $1.00 at Home Depot or any hardware store. They come cheaper by the dozen and can be widely distributed in every room and vehicle. Just the high profile of their accessibility keeps the kids in line.