A possessor of land has no privilege to use force intended or likely to cause death or serious harm against another whom the possessor sees about to enter his premises or meddle with his chattel, unless the intrusion threatens death or serious bodily harm to the occupiers or users of the premises. A possessor of land cannot do indirectly and by a mechanical device that which, were he present, he could not do in person. Therefore, he cannot gain a privilege to install, for the purpose of protecting his land from intrusions harmless to the lives and limbs of the occupiers or users of it, a mechanical device whose only purpose is to inflict death or serious harm upon such as may intrude, by giving notice of his intention to inflict, by mechanical means and indirectly, harm which he could not, even after request, inflict directly were he present.
A husband and wife trespassed into an abandoned and uninhibited house, where they found several old bottles and fruit jars which they took and added to their collection of antiques. They decided to go back a second time. Little did they know that the owners of the house had been aware that of a series of trespassing and housebreaking events over the years with loss of some household items so they boarded up the house and made a 20-gauge spring shotgun trap in one of the bedrooms. Upon entering that room, the husband was shot in the leg and lost his leg, resulting in permanent deformity. He was also in the hospital for 40 days. The trespassers filed for damages resulting in the injury, which was awarded by the trial court. The case was appealed to the Supreme Court of the Iowa.
Can an owner protect personal property in an unoccupied boarded-up farmhouse against trespassers and thieves by a spring gun capable of inflicting death or serious injury?
The Court held that the law has always placed a higher value upon human safety than upon mere rights in property. It is the accepted rule that there is no privilege to use any force calculated to cause death or serious bodily injury to repel the threat to land or chattels, unless there is also such a threat to the defendant's personal safety as to justify self-defense. The possessor may of course take some steps to repel a trespass but only that amount which is reasonably necessary to effect the repulse. Thus, spring guns and other man-killing devices are not justifiable against a mere trespasser, or even a petty thief. They are privileged only against those upon whom the landowner, if he were present in person, would be free to inflict injury of the same kind. Moreover, if the trespass threatens harm to property only--even a theft of property--the possessor is not privileged to use deadly force. He may not arrange his premises so that such force is inflicted by mechanical means. If he does, he will be liable even to a thief who is injured by such device.