Apparently, it is standard operating procedure in most of the U.S… It looks like it grew out of the Parental Responsibility Laws that were all the rage in the mid-90’s.
California: Juvenile Delinquency - juvenile_famlaw_selfhelp
Parental responsibilities when your child is arrested As a parent (or guardian) you have legal responsibilities. You may also have financial responsibilities for any damage caused by your child. You may have to pay the victim if the court orders “restitution.” Restitution is money to compensate for losses or damage caused by your child. For example, you may have to pay for what your child stole, or for the victim’s medical bills or lost wages. You may also have to pay for your child’s lawyer, juvenile hall services (like food and laundry), and fees to keep your child at the Department of Corrections and Rehabilitation. This can be expensive, so talk to the court about your financial ability to pay for these fees and costs.
