California prosecutors say a couple starved 12 of their 13 children to the point that their growth was stunted and a 29-year-old daughter weighed just 82 pounds.

They say they chained the kids to beds for months at a time, kept them from using the toilet and let them shower just once a year.

Riverside County District Attorney Mike Hestrin said Thursday that David and Louise Turpin at first just neglected their children, but eventually it turned into severe, prolonged abuse.

The Turpins pleaded not guilty later in the day to multiple counts of torture, child abuse and false imprisonment, charges that could get them life in prison.

Hestrin said that when a 17-year-old daughter fled and called authorities on Sunday it was the culmination of two years of planning.