Prosecutors say 17 year-old Austin Sigg allegedly confessed to killing a 10-year-old Colorado girl and also sexually assaulted her.

Westminster Police

Sigg is also accused in a separate attack on a 22-year-old woman. Yesterday he was charged with 17 counts in both cases. They include four murder charges, including one for both murder and sexual assault. Jessica disappeared Oct. 5 on a walk to school. Her house in Westminster is about a mile from where Sigg lived with his mother. A phone call to police from Sigg's mother last week led to his arrest.

Eight members of Jessica Ridgeway's family watched the proceedings, including her mother. Each wore purple, Jessica's favorite color. Sigg didn't speak during the brief court hearing in Golden. Defense attorneys will be asking the judge to send the case to juvenile court.

Click here for more:CBS