Mo. Rev. Stat. § 474.360
474.360 Written will valid if executed in compliance with law.
474.360. Written will valid if executed in compliance with law. — A written will is valid if executed in compliance with:
(1) The laws of this state;
(2) The laws, as of the time of execution, of the place where the will is executed; or
(3) The laws of the place where, at the time of execution or the time of the testator's death, the testator is domiciled, has a place of abode or is a national.
(L. 1980 S.B. 637) Effective 1-01-81