To be eligible for appointment as a detention officer, a person who was not employed as a detention officer before September 1, 2005, must:
(1) be at least 21 years of age;
(2) have acquired a high school diploma or its equivalent;
(3) have satisfactorily completed the course of preservice training or instruction required by the department;
(4) have passed the tests or examinations required by the department; and
(5) possess the level of certification required by the department.