The 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 17-year-old Austin Sigg said the defence had waived its right try to move the case to juvenile court.
Prosecutors say Sigg, who has confessed to killing Jessica Ridgeway and to attacking the runner, also sexually assaulted the young girl.
He was charged as an adult last month.
Judge Munsinger also agreed to move him to an 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.
He turns 18 in January and Judge Munsinger noted that he would have been moved to adult jail after that anyway.
Colorado law prevents prosecutors from seeking the death penalty because Sigg is a minor, even though he is being tried as an adult.
The teenager lived about a mile from the schoolgirl, whose dismembered body was found in a field five days after she went missing from her home in the Denver suburb of Westminster on October 5.
Acquaintances have said Sigg was interested in mortuary science and forensic science, often wore black and hung out in the high school cafeteria's "goth corner".