Generally speaking, under personal injury law an owner of property may not use deadly force to defend the property. Society values human life and bodily integrity much more than property. Therefore, the life, health and safety of an individual, even an intruder, is considered to be more valuable than the china or stereo, which that individual is trying to steal.
An owner is not prohibited, however, from invoking self-help methods in defending property from another. An owner of property is entitled to use reasonable force to prevent someone, or something, from entering onto his of her property or to remove something from his or her property. What, under normal circumstances, may constitute a battery, assault or other intentional tort, will not be considered unlawful in situations where it is performed as a reasonable use of self-help in defense of property. However, the use of force calculated to do great bodily harm, or cause death, is not permitted.
There is one narrow limitation upon the use of deadly force, where it is allowed. Where an intruder threatens personal safety, as well as a threat to property, or where the intruder is committing a forcible felony, deadly force may be appropriate.