Wyo. R. Prac. & P. 12.2
If a defendant intends to rely upon the defense of mental illness or deficiency at the time of the alleged offense, the defendant shall enter a plea of not guilty by reason of mental illness or deficiency at arraignment. For good cause the court may permit the plea to be entered at a later time. If there is a failure to comply with the requirements of this subdivision, evidence of mental illness or deficiency may not be introduced.
If a defendant intends to introduce expert testimony relating to a mental illness or deficiency or any other mental condition of the defendant bearing upon the issue of guilt, the defendant shall, within the time provided for the filing of pretrial motions or at such later time as the court may direct, notify the attorney for the state in writing of such intention and file a copy of such notice with the clerk. The requirement of this subdivision is in addition to the disclosures required by Rule 12.3. The court may for cause shown allow late filing of the notice or grant additional time to the parties to prepare for trial or make such other order as may be appropriate.
Upon the entry of a plea of not guilty by reason of mental illness or deficiency under W.S. 7-11-301 et seq., the court shall order an examination as required by statute. No statement made by the defendant in the course of any examination or treatment and no information received by any person in the course thereof is admissible in evidence in any criminal proceeding on any issue other than that of the mental condition of the defendant except that if the defendant testifies, any statement made by the defendant in the course of examination or treatment pursuant to W.S. 7-11-301 et seq., may be admitted:
If there is a failure to give notice when required by subdivision (b) or to submit to an examination when ordered under subdivision (c), the court may exclude the testimony of any expert witness offered by the defendant on the issue of the defendant's defense of mental illness or deficiency.
Evidence of a plea or notice given under subdivision (b), later withdrawn, is not, in any civil or criminal proceeding, admissible against the defendant.
Nothing in this rule is intended to expand the circumstances where a claim of mental illness or deficiency or any other mental condition may be raised.
Rule 12.3 Notice of defense of unconsciousness, automatism, or traumatic automatism.
Upon written demand of the attorney for the state, stating the time, date, and place at which the alleged offense was committed, the defendant shall serve within 10 days, or at such different time as the court may direct, upon the attorney for the state, a written notice of the defendant's intention to offer a defense of unconsciousness, automatism, or traumatic automatism. Such notice by the defendant shall state with particularity the facts upon which the defendant relies to justify the defense of unconsciousness, automatism, or traumatic automatism and the name and addresses of the witnesses upon whom the defendant intends to rely to establish such defense.
Upon the filing of such notice by the defendant, the court shall order an examination of the defendant by a designated examiner. A written report of such examination shall be filed with the clerk of court, and the report shall include detailed findings and an opinion of the examiner as to whether the defendant did suffer from unconsciousness, automatism, or traumatic automatism at the time of the alleged offense. The clerk of court shall furnish copies of the report to the attorney for the state and the defendant or the defendant's counsel.
Within 10 days after the examiner's report is served upon the attorney for the state, but in no event not less than 10 days before trial unless the court otherwise directs, the attorney for the state shall serve upon the defendant or the defendant's attorney a written notice stating the names and addresses of the witnesses upon whom the state intends to rely to establish that the defendant did not, at the time of the alleged offense, suffer from unconsciousness, automatism, or traumatic automatism and any other witnesses, to be relied upon to rebut testimony of any of the defendant's witnesses relating to such a defense.
If prior to or during trial, a party learns of an additional witness whose identity, if known, should have been included in the information furnished under subdivision (a) or (b) the party shall promptly notify the other party or the attorney for the other party of the existence and identity of such additional witness.
Upon the failure of either party to comply with the requirements of this rule, the court may exclude the testimony of any undisclosed witness offered by such party as to the defense of unconsciousness, automatism, or traumatic automatism. This rule shall not limit the right of the defendant to testify on the defendant's own behalf.
For good cause shown, the court may grant an exception to any of the requirements of subdivisions (a) through (e).
Evidence of an intention to rely upon the defense of unconsciousness, automatism, or traumatic automatism later withdrawn, or of statements made in connection with such intention, is not, in any civil or criminal proceeding, admissible against the person who gave notice of the intention.
Wyo. R. Prac. & P. 12.2