The purpose of the Sex Offender Commitment Act is to provide for the court-ordered treatment of sex offenders who have completed their sentences but continue to pose a threat of harm to others. It is the public policy of the State of Nebraska that dangerous sex offenders be encouraged to obtain voluntary treatment. If voluntary treatment is not obtained, such persons shall be subject to involuntary custody and treatment only after mental health board proceedings as provided by the Sex Offender Commitment Act. Such persons shall be subjected to emergency protective custody under limited conditions and for a limited period of time.