1. Persons committed to the department as criminal sexual psychopaths under statutes in effect before August 13, 1980, shall remain committed under those statutes, except as provided in this section.

2. At any time after commitment, a written application setting forth facts showing that the person committed as a criminal sexual psychopath has improved to the extent that his release will not be incompatible to the welfare of society may be filed with the committing court. The court shall issue an order returning the person to the jurisdiction of the court for a hearing. This hearing shall in all respects be like the original hearing under the statutes in effect before August 13, 1980, to determine the mental condition of the defendant. Following the hearing, the court shall issue an order to cause the defendant either to be placed on probation for a minimum period of three years, or to be returned to the department to continue his commitment; except that upon the expiration of the probationary period and after further hearing by the court, the person may be discharged. When the defendant is placed on probation or discharged, notice of such action shall be given immediately to the law enforcement authorities of the city and county of residence of the defendant, and the city and county where the defendant is to be released.