Colorado teen charged as adult in killing of 10-year-old girl GOLDEN, Colo. - Prosecutors say a teenager who allegedly confessed to killing a 10-year-old Colorado girl and attacking a runner also sexually assaulted the girl. Seventeen-year-old Austin Sigg was charged as an adult with 17 counts in both cases Tuesday. They include four murder charges, including one for both murder and sexual assault. Sigg didn't speak during the brief court hearing in Golden and didn't look at his relatives in the audience. Eight relatives of Jessica Ridgeway of Westminster also watched proceedings, including her mother. Each wore purple, Jessica's favorite color. Defense attorneys anticipate asking the judge to send the case to juvenile court.