Idaho Code § 41-257
The state fire marshal shall be the chief arson investigation officer in the state, and shall have the same responsibility and power in arson investigation as a county sheriff. He shall not, however, interfere at any time in the operation or administration of any fire department or sheriff's office except in matters of fire prevention and arson investigation when requested by the local fire jurisdiction, sheriff's office or written and signed complaint of any person served by the local fire jurisdiction. No person, acting without malice, shall be subject to civil liability for libel or otherwise, by virtue of the filing of complaints, requests, reports or furnishing other information pursuant to this section or required by the director of the department of insurance or the state fire marshal as a result of the authority herein granted.
Idaho Code § 41-257