Black-letter propositions
- 01
A private person's power to arrest is narrower than a police officer's; California Penal Code section 837 allows a private person to arrest for a public offense committed or attempted in his presence, for a felony that was in fact committed even if not in his presence, and for a felony he has reasonable cause to think the arrested person committed once a felony has in fact been committed.
- 02
A merchant may detain a person for a reasonable time, in a reasonable manner, to investigate when the merchant has probable cause to believe the person took or tried to take merchandise, and may use a reasonable amount of nondeadly force to protect himself and prevent escape; detention that is unreasonable in length or manner is false imprisonment.
- 03
A person may use necessary force to protect the person or property of oneself or of a family member or other listed person, but deadly force may not be used to protect property alone, and a spring gun or similar device is not privileged where the owner could not use the same force in person (Katko v. Briney).
- 04
California Penal Code section 692 allows lawful resistance to the commission of a public offense by the party about to be injured or by other parties, so a bystander may act to prevent a crime.
- 05
Public necessity is a complete privilege to interfere with private property to protect the community from a greater harm, and the actor is not liable for damages.
- 06
Private necessity privileges an entry or use of another's property to protect oneself or one's property from serious harm, but it is an incomplete privilege: the actor must pay for actual damage, is not liable for nominal or punitive damages, and the owner may not eject the actor while the emergency lasts.
- 07
A parent's privilege to discipline a child reaches only reasonable force; California's child-cruelty statute, for example, punishes willful infliction of cruel or inhuman corporal punishment or an injury resulting in a traumatic condition.
Use this attack sequence under time
Frame the issue
Identify who acted and what authority the law gives that person: officer, merchant, private citizen, owner, family member, or parent.
Resolve the next checkpoint
Check whether the facts satisfy the privilege's trigger, such as a public offense in the actor's presence or probable cause of theft.
Resolve the next checkpoint
Test the force and the duration: was it reasonable, nondeadly if property was the only interest, and no longer than needed?
Finish the conclusion
For necessity, decide whether the harm avoided was public or private, then ask what damages the actor still owes.
Common wrong turns
- A private citizen who arrests on a reasonable but mistaken belief that a felony occurred may lose the privilege if no felony in fact occurred.
- A merchant's privilege is limited by reasonable time and manner, and it does not permit deadly force or a lengthy confinement to extract a confession.
- Private necessity excuses the entry but not the damage; public necessity excuses both.
Worked example
During a blizzard, a hiker forces open an unoccupied cabin to survive, burns some of the owner's furniture for heat, and leaves the next morning.
The hiker's entry is privileged by private necessity, since the risk to his life was serious and no less harmful choice existed. The privilege is incomplete, so he must pay for the furniture and any damage to the cabin, but the owner cannot recover punitive or nominal damages for the entry itself.
Practice this topic
Arrest and merchant detention
California Penal Code section 837 lists when a private person may arrest another: for a public offense committed or attempted in his presence, when the person arrested has committed a felony although not in his presence, and when a felony has in fact been committed and he has reasonable cause for believing the person arrested committed it. The statute gives a private person less room for mistake than a police officer has, since the felony must in fact have happened for the third ground.
Section 490.5(f) allows a merchant to detain a person for a reasonable time for the purpose of conducting an investigation in a reasonable manner whenever the merchant has probable cause to believe the person is attempting to take or has taken merchandise from the premises. The merchant may use a reasonable amount of nondeadly force necessary to protect himself and to prevent escape of the person detained or the loss of property. Cornell's Wex entry on false imprisonment describes the same shopkeeper's privilege as an affirmative defense allowing detention for a reasonable time and in a reasonable manner.
Defense of family, property and public order
California Civil Code section 50 provides that any necessary force may be used to protect from wrongful injury the person or property of oneself, or of a spouse, child, parent, or other relative, or member of one's family, or of a ward, servant, master, or guest. The word necessary limits the privilege. In Katko v. Briney, the Iowa Supreme Court upheld liability against a landowner who set a spring gun in an unoccupied farmhouse. The court said an owner may not use force that takes life or inflicts great bodily injury against a trespasser, or set a device likely to do so, except where the trespasser is committing a felony of violence or endangering life.
California Penal Code section 692 allows lawful resistance to the commission of a public offense by the party about to be injured and by other parties. Cornell's Wex entry on trespass says a landowner may use reasonable force to stop a trespasser's entry, but if the landowner seriously injures a trespasser who threatens no harm, the landowner is liable.
Necessity and parental discipline
Cornell's Wex entries distinguish public from private necessity. Public necessity is an absolute defense to trespass when the defendant interferes with property in an emergency to protect the community from a greater harm, and the defendant is not liable for damages. Private necessity justifies the entry but does not relieve liability for actual damages, and the defendant is not liable for nominal or punitive damages. The Wex entry on trespass adds that if there are no actual damages the privilege is a complete defense, and that a landowner has no right to eject a person while the emergency continues and is liable if the person is harmed after being expelled.
In Vincent v. Lake Erie Transportation Co., a ship owner who kept his vessel moored to a dock during a storm was held liable for the damage the ship did to the dock, even though prudent seamanship required staying. The court reasoned that a person who takes another's property under necessity must pay for it. California Penal Code section 273d, which punishes willful infliction of cruel or inhuman corporal punishment or an injury resulting in a traumatic condition on a child, shows the outer boundary of discipline.
Frequently asked questions
What is the controlling rule for privileges of authority and necessity: arrest, merchants, family defense, and incomplete privilege?+
Name the privilege, state its trigger and limits, apply each to the actor's conduct, and finish with the damages the actor still owes if the privilege is incomplete.
When may a private person arrest in California?+
For a public offense committed or attempted in his presence, or for a felony that has in fact been committed, under Penal Code section 837.
What limits a merchant's power to detain a suspected shoplifter?+
The merchant needs probable cause and may detain only for a reasonable time in a reasonable manner, using reasonable nondeadly force, under Penal Code section 490.5(f).
Can an owner use a spring gun to protect property?+
No, under Katko v. Briney, an owner may not set a device likely to take life or inflict great bodily injury to protect property alone, except in narrow cases such as a felony of violence.
What is the difference between public and private necessity?+
Public necessity is a complete defense, and private necessity excuses the entry but requires payment for actual damage, per Cornell's Wex entries.
Does private necessity make the actor pay punitive damages?+
No. Wex says the actor pays actual damages but is not liable for nominal or punitive damages.