Colo. Rev. Stat. § 16-5-209
The judge of a court having jurisdiction of the alleged offense, upon affidavit filed with the judge alleging the commission of a crime and the unjustified refusal of the prosecuting attorney to prosecute any person for the crime, may require the prosecuting attorney to appear before the judge and explain the refusal. If after that proceeding, based on the competent evidence in the affidavit, the explanation of the prosecuting attorney, and any argument of the parties, the judge finds that the refusal of the prosecuting attorney to prosecute was arbitrary or capricious and without reasonable excuse, the judge may order the prosecuting attorney to file an information and prosecute the case or may appoint a special prosecutor to do so. The judge shall appoint the special prosecutor from among the full-time district attorneys, assistant district attorneys, or deputy district attorneys who serve in judicial districts other than where the appointment is made; except that, upon the written approval of the chief justice of the supreme court, the judge may appoint any disinterested private attorney who is licensed to practice law in the state of Colorado to serve as the special prosecutor. Any special prosecutor appointed pursuant to this section shall be compensated as provided in section 20-1-308, C.R.S.
C.R.S. § 16-5-209