Tennessee Code Title 38. Prevention and Detection of Crime § 38-7-109

(a) When a death is reported as provided in § 38-7-108, it is the duty of the county medical examiner in the county in which the death occurred to immediately make an investigation of the circumstances of the death.  The county medical examiner shall record and store the findings, and transmit copies according to the death investigation guidelines developed by the Tennessee medical examiner advisory council.  In any event the county medical examiner is authorized to remove from the body of the deceased a specimen of blood or other body fluids, or bullets or other foreign objects, and to retain such for testing and/or evidence if in the county medical examiner's judgment these procedures are justified in order to complete the county medical examiner's investigation or autopsy.

(b) When an autopsy is ordered by the district attorney general, the county medical examiner shall notify the chief medical examiner and the county medical examiner may perform the autopsy or shall designate and authorize a pathologist to perform the autopsy as provided in § 38-7-105.