La. Public Health and Safety § 40:1566
Under the direction of the fire marshal, the chief of the fire department in each municipality where a fire department is established, the chief officer of each special fire protection district created under Part I of this chapter, the town marshal of towns and villages which have no fire department, or the sheriff of each parish, insofar as the territory outside the limits of any incorporated municipality or of any special fire protection district is concerned, shall investigate the cause, origin, and circumstances of every fire occurring within their respective jurisdictions. This investigation shall specifically determine, insofar as possible, the cause of and circumstances surrounding the fire. The investigation shall be made at the earliest possible time following the start of the fire. The officer making the investigation shall immediately notify the fire marshal if the circumstances indicate that the possible cause of the fire is human design or criminal neglect. Upon receiving such a report of possible arson or fire caused by design or criminal neglect, the fire marshal shall assign one or more deputies to direct the investigation.
Local officers making investigations hereunder shall transmit monthly a written statement of all facts relating to the cause and the origin of the fire, the kind, value, and ownership of the property destroyed or damaged, the amount of insurance which may have been in force upon the property at the time of the fire, and any other information called for by the fire marshal.
The fire marshal shall keep in his office a record of each fire occurring in the state, together with all facts, statistics, and circumstances thereof, including the origin of the fire, that have been determined by the investigations provided for in this section or otherwise.
La. Public Health and Safety § 40:1566