(a) The state fire marshal shall immediately investigate a fire occurring in this state in which property is destroyed if the commissioner directs the investigation or, in the discretion of the commissioner, if the investigation is requested by:
(1) the mayor, fire chief, fire marshal, or police chief of a municipality in which a fire occurs;
(2) a county or district judge, sheriff, county fire marshal, chief or fire marshal of a fire department in an unincorporated area, or county attorney of a county in which a fire occurs;
(3) a fire insurance company interested in a loss or the company’s general, state, or special agent;
(4) an insurance policyholder, property owner, or lessee sustaining a fire loss;
(5) a justice of the peace or a constable of a precinct in which a fire occurs; or
(6) officials of a state or federal law enforcement agency or local or special governmental district involved or interested in a fire loss that occurred in this state.
(b) The state fire marshal at any time may enter a building or premises at which a fire is in progress or has occurred and is under control of law enforcement or fire service officials to investigate the cause, origin, and circumstances of the fire. If control of the building or premises has been relinquished, entry must be in compliance with search and seizure law and applicable federal law.

(c) The state fire marshal shall conduct the investigation at the place of the fire and before an insured loss may be paid. The state fire marshal shall ascertain, if possible, whether the fire was caused intentionally, carelessly, or accidentally. The state fire marshal shall make a written report of the investigation to the commissioner.
(d) If the state fire marshal believes that further investigation is necessary, the state fire marshal shall take sworn statements from persons who in his opinion can supply relevant information and shall have the statements put in writing. The state fire marshal may administer oaths and compel the attendance of witnesses and the production of documents.
(e) If the state fire marshal believes that there is sufficient evidence to charge a person with arson, attempted arson, conspiracy to commit fraud, or another offense related to the matter under investigation, the state fire marshal shall give to the appropriate prosecuting attorney all evidence and relevant information that has been obtained, including the names of witnesses. The state fire marshal shall arrest the person if the person has not been arrested by some other authority. The state fire marshal shall assist in the prosecution of any complaint he files.
(f) The state fire marshal may, in his discretion, conduct or direct the conduct of an investigation in private and may exclude from the place of the investigation persons not needed for the investigation. Witnesses may be separated from each other and not be allowed to communicate with other witnesses until after they have testified.
(g) The state fire marshal may elect to withhold from the public any testimony taken in an investigation under this section.