Colorado Revised Statutes Title 18. Criminal Code § 18-3-412.6. Failure to verify location as a sex offender

(2)(a) In a prosecution for a violation of this section, it is an affirmative defense that:

(b) In order to assert the affirmative defense pursuant to this subsection (2), the defendant shall provide notice to the prosecuting attorney as soon as practicable, but not later than thirty days prior to trial, of his or her notice of intent to rely upon the affirmative defense. The notice shall include a description of the uncontrollable circumstance or circumstances and the dates that the uncontrollable circumstances began and ceased to exist in addition to the names and addresses of any witnesses the defendant plans to call to support the affirmative defense. The prosecuting attorney shall advise the defendant of the names and addresses of any additional witnesses who may be called to refute the affirmative defense as soon as practicable after their names become known. Upon the request of the prosecution, the court shall first rule as a matter of law whether the claimed facts and circumstances would, if established, constitute sufficient evidence to support submission to the jury.