Torts - Cases, Principles, and Institutions Fifth Edition, 2016a

Witt & Tani, TCPI 2. Intentional Harms
and the wall had proved ineffective against thieves. In an era of negligible police
protection, a spring gun may have been the most cost-effective means of protection
for the tulips. But since spring guns do not discriminate between the thief and the
innocent trespasser, they deter owners of domestic animals from pursuing their
animals onto other people’s property and so increase the costs (enclosure costs or
straying losses) of keeping animals. The court in Bird implied an ingenious
accommodation: One who set a spring gun must post notices that he has done so.
Then owners of animals will not be reluctant to pursue their animals onto property
not so posted. A notice will be of no avail at night, but animals are more likely to
be secured then and in any event few owners would chase their straying animals
after dark.
RICHARD A. POSNER, ECONOMIC ANALYSIS OF LAW 260-61 (8th ed. 2011). If this is the right way
to think about Bird v. Holbrook (is it?), what explains the court’s decision to place the obligation
to avoid the conflict between the two activities on the tulip growers rather than on the pea-fowl
farmers? The tulip grower has at least built a wall. Should the plaintiff be able to sue the peafowl
farmer for the effects of his failure to keep the pea-fowl contained?
Note Judge Posner’s reference to the negligible police protection of 1820s Great Britain.
We no longer live in such an era—at least not in developed countries. Does this matter for the
analysis? What about technological changes? Should spring guns or other dangerous traps be
allowed even with notice in defense of private property now that inexpensive digital cameras
promise the possibility of constant surveillance?
2. Malicious traps. The use of spring guns and other traps by property owners looking for an
inexpensive way to defend their property—or to wreak private vengeance on thieves—has not
disappeared in the era of modern policing. Such traps raise questions of both criminal law, which
asks whether criminal punishment is appropriate, and tort law, which asks whether propertyowners
should be required to compensate for the injuries their traps cause, or should instead be
treated as having engaged in justified self-defense.
Probably the most celebrated (and reviled) instance of the use of spring gun traps is Katko
v. Briney, 183 N.W.2d 657 (Iowa 1971), near the beginning of the late-twentieth-century increase
in crime rates. The issue before the court in Katko was whether an owner “may protect personal
property in an unoccupied boarded-up farm house against trespassers and thieves by a spring gun
capable of inflicting death or serious injury.” After a series of break-ins to their vacant farmhouse
over a ten year period—break-ins that had resulted in considerable property damage and the theft
of household items—Mr. and Mrs. Briney decided to put a stop to the crimes once and for all. In
June 1967, they supplemented the “no trespass” signs on the property with boards on the windows
and doors and with a spring-loaded shotgun wired to fire when the door to a bedroom was opened.
In July 1967, a man named Katko entered the home to steal antique glass bottles and fruit
jars he had found on an earlier visit. After loosening a board on the porch window, Katko entered
the house with a companion and began to search it. On opening the north bedroom door, Katko
triggered the shotgun trap that the defendants had set. The 20-gauge spring shotgun fired, striking
Katko in the right leg above the ankle; much of his leg, including part of the tibia, was destroyed.
Katko later entered a guilty plea to larceny, stating that he knew “he had no right to break and
enter the house with the intent to steal.” The value of the jars and bottles was set at less than $20
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