In counties of the third class now or hereafter having a population in excess of 75,000 there may be appointed not in excess of 9 county detectives, of whom 1 may be designated chief of county detectives, 1 captain of county detectives; and 1 lieutenant of county detectives; their annual salaries shall be fixed as follows: chief of county detectives, not less than $7,500.00; captain of county detectives, not less than $7,000.00; lieutenant of county detectives, not less than $6,000.00; and other county detectives, not less than $5,500.00
N.J.S. § 2A:157-5