Douglas County authorities have named a suspect in the execution style killings of two Highlands Ranch teenagers earlier this year.
Nathanial York faces first degree murder charges in the deaths of 16 year old Shawn Cerniglia and 18-year-old Carrie Lynn Heiden. York is already on trial for attempted murder in Douglas County in connection with a shooting in Parker.
Cerniglia and Heiden's bodies were found in an Adams County field in May. A burned out car was also in the same area. Authorities believe the two were killed because they witnessed the incident in Parker.
Cerniglia and Heiden were last seen leaving Cerniglia's home