The Denver Post reported Wednesday that William Costello is charged with multiple counts of sexual assault, kidnapping and impersonating a police officer.
One alleged assault involved a 13-year-old girl.
Costello was being held on $200,000 bond. It wasn't immediately known if he had an attorney.
Costello was arrested Nov. 5 after DNA linked him to three attacks dating back to 2008.
His DNA was taken after an alleged assault on an anti-abortion protester in July.
A state law requires police to take DNA samples from anyone charged with a felony.
(Copyright 2012 by The Associated Press. All Rights Reserved.)