Notwithstanding any general or special law to the contrary, every person who receives an appointment to a position on a permanent full-time basis or on a reserve or intermittent basis in which said person will exercise police powers in a municipal police department, the Massachusetts bay transportation authority police, the department of correction, the state police, University of Massachusetts police, Massachusetts Port Authority police, the sheriffs and their employees, or the division of law enforcement within the department of fisheries, wildlife and environmental law enforcement shall, upon exposure to any known risk factor associated with HIV or AIDS as those terms are defined in Massachusetts General Laws Chapter 111, Section 2D, while exercising police powers, whether in the line of duty or as a good Samaritan, be eligible for testing to determine whether such person has contracted an HIV infection or its associated illnesses. Such testing shall be at the option of the exposed person and any portion of cost for three such tests undergone within eighteen months immediately following the date of exposure that is not covered under an insurance policy issued for the benefit of the exposed person shall be paid for by the Commonwealth. The exposed person shall also be eligible for psychiatric counseling in relation to such exposure. Such counseling shall be at the option of the exposed person and any portion of the cost for such counseling that is approved by the department of public health and the department of public safety that is not covered under an insured policy issued for the benefit of the exposed person shall be paid for by the Commonwealth.