DNA is unlocking the doors to ice-cold cases once believed unsolvable.
Samples from convicted felons led police to a suspect in the 1976 slaying of Columbine High student Holly Marie Andrews in Clear Creek County. Suspects also were identified in a string of violent rapes from 2004 and 2005 in Denver, Aurora and Arapahoe County.
Investigators with the Colorado Bureau of Investigation and the Clear Creek County Sheriff's Department arrested a suspect Feb. 1 in connection with the 1976 slaying of Andrews, who was 16 years old.