(b) The coroner or coroner and coroner's physician, or the medical examiner, also shall make or cause to be made, quantitative tests for alcohol, and for any trace of a controlled substance, as defined in section three thousand three hundred six of the public health law, that the coroner, coroner's physician or medical examiner has reasonable cause to believe is present, on the body of every operator of a motor vehicle or a pedestrian sixteen years of age or older who was involved in and died as a result of a motor vehicle accident; provided, however, such tests shall not be made pursuant to the provisions of this paragraph if such coroner, coroner's physician or medical examiner has reason to believe that the decedent is of a religious faith which is opposed to such test on religious or moral grounds. 4. A coroner, coroner's physician or medical examiner shall have power to subpoena and examine witnesses under oath in the same manner as a magistrate in holding a court of special sessions. 5. Notwithstanding section six hundred seventy of this article or any other provision of law, the coroner, coroner's physician or medical examiner shall promptly perform or cause to be performed an autopsy and to prepare an autopsy report which shall include a toxicological report and any report of any examination or inquiry with respect to any death occurring within his county to an inmate of a correctional facility as defined by subdivision three of section forty of the correction law, whether or not the death occurred inside such facility.