The following entities may apply for the appointment of special police officers for the following purposes: A municipal corporation, county, or other governmental body of the State, in order to protect property owned, leased, or regularly used by the governmental body or any of its units; Another state, or subdivision or unit of another state, that has an interest in property located wholly or partly in this State, in order to protect the property, as defined in Public Safety Article, §3-303, Annotated Code of Maryland; A college, university, or public school system in the State, in order to protect its property or students; or A firm, corporation, partnership, sole proprietorship, or other entity existing and functioning for a legitimate and legal business purpose, in order to protect its business property. The applicant for a commission shall be at least 18 years of age.