The court or jury commissioner with the approval of the court must discharge a person from serving as a trial juror in either of the following cases: (1) when it satisfactorily appears that the person is not competent; or (2) when it satisfactorily appears that the person should be excused under 3-15-313.
Discharge By Court Or Jury Commissioner
Mont. Code Ann. § 3-15-312, under Jurors -- Competency and Excuses.
Mont. Code Ann. § 3-15-312