Mo. Rev. Stat. § 633.160
If a person presents himself, or is presented, to a regional center or department developmental disability facility and is determined to be intellectually disabled or developmentally disabled and, as a result, presents an imminent likelihood of serious harm to himself or others as defined in chapter 632, the regional center or developmental disability facility may accept the person for detention for evaluation and treatment for a period not to exceed ninety-six hours under the same procedures contained in chapter 632. The head of the regional center or developmental disability facility may initiate guardianship proceedings to have the person detained beyond the ninety-six hours under chapter 475, or may refer the person to a mental health facility, if the person is mentally ill, for further detention under the procedures in chapter 632.
§ 633.160, RSMo