Tennessee Code Title 38. Prevention and Detection of Crime § 38-8-129

(a) A law enforcement officer who directly observes or has knowledge of excessive use of force by another law enforcement officer in violation of state or federal law shall, within the officer's scope of training, knowledge, and authority, intervene when the officer has an opportunity and means to prevent the harm from occurring. A law enforcement officer who intervenes during an excessive force incident shall report the circumstances to a supervisor as soon as practical.

(b) A law enforcement officer who has direct knowledge of excessive use of force by another law enforcement officer in violation of state or federal law shall, as soon as practical, report the excessive use of force to a supervisor.

(c) A law enforcement agency is prohibited from retaliating against any officer who intervenes against excessive use of force, reports excessive use of force, or cooperates in an internal investigation related to the excessive use of force.