(CBS/AP) DENVER - Austin Sigg, a 17-year-old accused of kidnapping and killing 10-year-old Colorado girl Jessica Ridgeway, is scheduled to appear in court on Tuesday.
Sigg is charged as an adult with murder, kidnapping and other crimes. He is accused of killing Ridgeway and also of attacking a 22-year-old jogger in May.
Prosecutors say Sigg confessed to both the murder and the jogging attack, but it is not clear if he made any comment on the accusation that he sexually assaulted the 10-year-old.
Sigg faces 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 faces charges of 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 as an adult, Sigg faces up to life in prison with the possibility of parole after 40 years. If he is convicted as a juvenile, he faces a maximum of seven years on each conviction, which could put him in prison for decades if he is ordered to serve his sentences consecutively.
In charging documents, prosecutors said Sigg acted alone in kidnapping, robbing, and sexually assaulting Jessica. The robbery charged involved the girl's backpack and water bottle, which were found in another suburb three days after she disappeared.
Jessica disappeared on the morning of Oct. 5 after leaving her home in the west Denver suburb of Westminster. Police arrested Sigg on Oct. 23.
Police say in the May attack, a 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. She managed to escape her attacker.