Mo. Rev. Stat. § 630.168: Suspected abuse to be reported.

If it is alleged or suspected that any patient, resident or client who has been admitted on a voluntary or involuntary basis to a mental health facility or mental health program in which people are detained pursuant to chapter 632, or any patient, resident or client in a residential facility, day program or specialized service operated, funded or licensed by the department is being or has been subjected to patient or resident abuse which results in physical injury, and in cases of sexual abuse, the head of the facility, program or service shall promptly notify local law enforcement authorities and cooperate fully with any investigation by them.