Arson under the Christmas tree

A rural mountain cottage fire was initially ruled as an accidental Christmas tree fire. The insurance company's Special Investigation Unit discovered information that prompted further fire scene investigation. The investigation included electrical, botanical, and chemical analysis, photograph metadata examination, simulations, and a series of full-scale, fully instrumented test burns. This paper reviews the investigation. Special emphasis will be placed on how the scientific method helped to prevent bias. The scene investigation resulted in evidence that the fire was likely intentionally set. The site inspection posed several challenges including schedule delays, inclement weather, an unusual ignition source, and multiple potential first fuels.