Mo. Rev. Stat. § 631.120: Involuntary detention — request by professionals — procedure — duration.

1. A mental health professional, peace officer, registered nurse, licensed physician, or qualified counselor may complete an application for detention, treatment, or rehabilitation for up to ninety-six hours under the procedures of section 632.305 for a person presenting an imminent likelihood of serious harm to himself or herself or others as a result of alcohol or drug abuse, or both.

2. If a peace officer has reasonable cause to believe that unless a person is taken into custody the likelihood of serious harm is imminent as a result of alcohol or drug abuse, or both, the officer may take the person into custody and convey him or her to an alcohol or drug abuse facility. The officer shall complete an application for detention indicating the facts upon which the belief is based.