DAN ELLIOTT, Associated Press | Tuesday, November 27, 2012

GOLDEN, Colo. (AP) — A teenager accused of kidnapping and killing a 10-year-old Colorado girl and attacking a runner will be prosecuted as an adult.

The judge presiding at a hearing for Austin Sigg, 17, on Tuesday said the defense had waived its right try to move the case to juvenile court. Prosecutors charged Sigg as an adult last month but Sigg's lawyers had the option of asking Judge Stephen Munsinger to move the case to juvenile court.

Munsinger also agreed to move Sigg to adult jail at the request of the state's juvenile justice system. Officials said Sigg is being held in an isolation cell not meant for long-term stays and requires full-time supervision.

Sigg turns 18 in January and Munsinger noted that he would have been moved to adult jail after that anyway.

Sigg is accused of killing Jessica Ridgeway, who disappeared on the morning of Oct. 5 as she was walking to school in the west Denver suburb of Westminster.

LawOfficer.com previous coverage:

• Jessica Ridgeway Kidnapping, Killing

He is also charged with a May attack on a 22-year-old jogger who escaped.

Prosecutors said he has confessed to kidnapping and killing Jessica and attacking the runner. It's not clear if he has made any comment on the charge of sexually assaulting Jessica.

Sigg is charged with four counts of murder, two counts of kidnapping, and one count each of sexual assault on a child and robbery in Jessica's abduction and slaying. He's charged with attempted murder, attempted sexual assault and attempted second degree kidnapping in the attack on the runner. Prosecutors also charged Sigg with six counts of crime of violence.

If convicted, Sigg could get up to life in prison with the possibility of parole after 40 years.

In charging documents, prosecutors said Sigg acted alone in kidnapping, robbing, and sexually assaulting Jessica. The robbery charge involved the girl's backpack and water bottle, which were found in another suburb three days after she disappeared.

Police arrested Sigg on Oct. 23. His mother told The Associated Press she called police and her son turned himself in.

Police said that in the May attack, the woman reported she was jogging when she was grabbed from behind by a man who placed a rag with a chemical smell over her mouth. Police have not said whether the rag was soaked with a chemical meant to subdue the woman.

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