As used in this Act:
All persons suffering from a mental disorder, which mental disorder has existed for a period of not less than one year, immediately prior to the filing of the petition hereinafter provided for, coupled with criminal propensities to the commission of sex offenses, and who have demonstrated propensities toward acts of sexual assault or acts of sexual molestation of children, are hereby declared sexually dangerous persons.
725 ILCS 205/1.01