A person suffering from a mental illness has no constitutional right to liberty as long as the mental illness exists. The state exercises control over the locomotion of such individuals to prevent injury either to the patient himself or to other citizens and property. Power to protect the patient flows from the general duty of the sovereign to care for the members of society, i.e., the parens patriae doctrine. Similarly, the state police power includes the power to safeguard citizens and their property."
Louis B. Loughren,
Release Procedure under the Pennsylvania Mental Health and Mental Retardation Act of 1966,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol5/iss4/6