A medical investigator must be a licensed emergency medical technician (EMT), paramedic, registered nurse, physician's assistant or a person registered by or a diplomat of the American Board of Medicolegal Death Investigators and approved by the county medical examiner as qualified to serve as medical investigator

If the county has an elected coroner, the coroner shall serve as the medical investigator for the county; provided, that the coroner meets the qualifications for a medical investigator. If the coroner is not qualified to serve as medical investigator, then the county legislative body shall, by resolution, either authorize the county medical examiner to appoint a medical investigator subject to confirmation by the county legislative body, or provide for this function through a contract for service approved by the county medical examiner and the county legislative body; provided, however, that, if the county has an elected coroner who has served in that capacity for ten years or more, the coroner shall serve as the medical investigator for the county, regardless of whether the coroner meets the qualifications set out inT.C.A. § 38-7-104(f)(1)

The county medical investigator may conduct investigations when a death is reported, as provided in T.C.A. § 38-7-108, under the supervision of the county medical examiner. The county medical investigator may make pronouncements of death and may recommend to the county medical examiner that an autopsy be ordered. However, the county medical investigator shall not be empowered to sign a death certificate. The county medical examiner may delegate to the county medical investigator the authority to order an autopsy.

T.C.A. § 38-7-104(f).