Since arson is an afirmative defense to an action on the insurance policy, the insurer has the burden of proof in establishing each of the necessary elements (the incendiary origin of the fire and the insured's responsibility for the burning). For example, it must be shown that the fire has not resulted from such potential causes as the electrical system, faulty electrical equipment, or careless smoking. The insurer may use any evidence obtained in an investigation of a suspected arson fire, even if there is no consent given by the insured for the intrusion. However, since most of the evidence is usually circumstantial, the insured's counsel may object to it by claiming that the jurors are improperly allowed to pile one inference upon another in reaching a decision. Thus, each inference should be drawn from separate and independent facts. Another problem faced by the insurer may be that jurors, and possibly some judges, may feel that a verdict for the insurance company would brand the insured as a criminal, thus making them reluctant to find for the insurer. To reduce these obstacles, alternative defenses should be used. For example, any attempt, by the insured, to deceive the insurer by overstating a loss provides the insurance company a viable alternative to the arson defense. The problem of joint and corporate insureds, the hazards of denying liability, and relevant case law are discussed. Particular emphasis on laws applicable to Missouri is provided. A total of 238 footnotes are included.