Fire Prevention and Investigation - As enacted, requires certification from the peace officer standards and training commission and certain other criteria to be met in order for the commissioner of commerce and insurance, the commissioner's deputies, a municipal fire investigator, or a salaried county fire investigator to exercise police powers, including the power to arrest, relative to cases of arson or suspected arson. - Amends TCA Title 5; Title 6; Title 38 and Title 68.

HB 1870 requires specific fire investigators in Tennessee to hold a current certification from the Peace Officer Standards and Training Commission (POST) before they can exercise police powers - such as making arrests - in arson or suspected arson cases. This applies directly to the Commissioner of Commerce and Insurance and their deputies, municipal fire investigators, and salaried county fire investigators when using police authority. The bill does not require certification for routine fire origin investigations conducted without police powers. Certification must be obtained by January 1, 2027, and includes meeting police officer qualifications and completing approved training. The bill amends Tennessee Code Sections 68-102-127 and 38-8-107.