Missouri Revised Statutes Title XII. Public Health and Welfare § 197.145. At-risk behavioral health patient may be detained, when--immunity from liability, when

1. Notwithstanding any other provision of law to the contrary, including chapter 632, when an at-risk behavioral health patient, as such term is defined in section 190.240, receives treatment at a hospital, the treating physician may temporarily hold the patient for further behavioral health assessment and, if necessary, for transfer to an appropriate treatment facility, if the physician has reason to believe that the patient is at imminent serious risk of harming themselves or others.

2. In no circumstance shall an at-risk behavioral health patient be detained in a temporary hold under this section for a period longer than necessary for an evaluation and, if necessary, transfer to an appropriate treatment facility. If, after the evaluation, the treating physician has reasonable cause to believe that the patient is not at imminent serious risk of harming themselves or others, the patient shall be immediately released from the temporary hold.

3. A physician employing a temporary hold under this section, and any other health care professional or other personnel at the hospital working to treat or transfer the patient, as well as any emergency medical services personnel or law enforcement officers who may be acting to detain or transport the patient under this section, shall not be civilly liable for the temporary hold, treatment, or transport of a patient if such actions are carried out in good faith and without gross negligence for a purpose authorized by this section.