Tennessee Code Title 23. Attorneys-At-Law § 23-2-105

(a) Notwithstanding any other law or rule of court to the contrary, an attorney licensed to practice law in this state or the attorney's agent shall be authorized to serve subpoenas on witnesses in any civil or criminal case if service is effectuated in accordance with subsection (b) and if the attorney or any member of the attorney's firm is involved in the case for which the subpoenas are issued.

(b) In order for service under this section to be effective, the name of both the attorney and the attorney's agent, if any, shall be written on the subpoena and both persons shall sign the subpoena. The subpoena shall be served in person by either the attorney or the agent whose name appears on the subpoena, and the person effectuating service shall file with the issuing clerk an affidavit of return stating that the subpoena was served, the identity of the person served and the date, place and manner of service. An agent may serve a subpoena under this section only if the agent is eighteen (18) years of age or older. The attorney shall be responsible for the actions of the attorney's agent serving the subpoena in accordance with generally accepted principles of agency law.