THORNTON, Colo. (CBS4)– Police in Washington state have arrested a man wanted for sexual assaulting a 9-year-old girl.

Steve Allen Pierce, 35, was arrested Wednesday morning by police in Everett, Washington. He is being held in the Snohomish County Jail awaiting extradition to Colorado.

Pierce was wanted for a sexual assault that occurred last month in Thornton. Police in Thornton were called to North Suburban Medical Center at 9191 North Grant Street in reference to a report of a sexual assault victim at that location.

The victim was transported to The Children’s Hospital as a result of her injuries.

Police said that their preliminary investigation revealed the 9-year-old female victim and Pierce knew each other. Police said the girl had been sexually assaulted May 26 about 10 p.m. in the 9100 block of N. Huron Street in Thornton.

Police obtained an arrest warrant for Pierce, 35, on the following charges: sexual assault on a child and sexual assault on a child- position of trust.

(credit: CBS)

(credit: CBS)

CBS4 Investigator Brian Maass reviewed hundreds of pages of Pierce’s parole file and found the Colorado Division of Adult Parole apparently made some serious, glaring mistakes in their supervision of Pierce. Watch Maass’ in-depth report on CBS4 News at 10 on Wednesday.