(CNN) -- A teenager accused of killing 10-year-old Jessica Ridgeway in Westminster, Colorado, pleaded guilty to all counts, a spokesman for Colorado's courts said Tuesday.
Austin Reed Sigg was 17 at the time of the killing and was charged as an adult. He lived about one mile from Ridgeway's home.
A judge accepted his plea, and sentencing is set for November 18 and 19, said spokesman Rob McCallum.
Sigg was accused of strangling Ridgeway, dismembering her and placing some of her body parts in a crawlspace under his family's home.
Police found parts of her body at a park five miles away five days after the bespectacled blonde girl disappeared while walking to Witt Elementary School on October 5.
A break in the investigation came when Sigg's mother called 911 and handed him the phone. Sigg, police said, confessed.
In Session's Jessica Thill contributed to this report.