In California, negligence per se is a legal principle in which you are presumed to have acted negligently if you violate a statute and, in so doing, injure someone that the statute was designed to protect. The theory arises in the context of personal injury and wrongful death lawsuits.
Here are five key things to know:
- Evidence Code 669 is the California statute that outlines the negligence per se doctrine.
- Negligence per se is a rebuttable presumption: Once you establish it, the defendant can counter or challenge it.
- One way defendants can rebut this presumption is by showing their violation of the statute was reasonable under the circumstances.
- Negligence per se is a common cause of action in car accident cases involving traffic law violations.
- Res ipsa loquitor is a similar but separate legal doctrine that establishes negligence by using circumstantial evidence.
In this article, the California personal injury attorneys at the Shouse Law Group law firm will answer the following questions:
- 1. What is the legal definition of negligence per se in California?
- 2. How is the presumption of negligence rebutted?
- 3. What are the defenses to negligence per se cases?
- 4. How does negligence per se differ from res ipsa loquitor?
1. What is the legal definition of negligence per se in California?
The doctrine of negligence per se is a theory in personal injury cases that a person is presumed to have acted negligently if they injured someone in the course of violating a statute.
1.1. How is negligence different from negligence per se?
Ordinary negligence cases occur when a defendant:
- does something that a reasonable person would not do under the circumstances, or
- fails to do something that a reasonable person (person of ordinary prudence) would do in the same situation.1
To recover damages in a California personal injury claim for negligence, you have to prove:
- the defendant acted with negligence, and
- this negligence was a substantial factor in causing harm to you.
Negligence per se (also called negligence “as a matter of law”) is a theory that makes it easier for you to prove a negligence cause of action and recover damages.
Under the doctrine, a defendant’s acts are presumed to be unreasonable as soon as they violate a statute. These cases are very common in the context of car accidents.
Example: Hector hits another car after reckless driving in Los Angeles, causing Stacy a broken leg. If Stacy sues under a per se negligence theory, Hector is presumed to have acted negligently because he broke the law by reckless driving. Stacy does not have to make a separate showing that he was unreasonable.
1.2. When is negligence presumed?
A defendant is presumed negligent as a matter of law when:
- they violated a statute, ordinance, or regulation,
- the violation caused death or injury to you,
- the death or injury was the type of harm that the statute was designed to prevent, and
- you were a person that the statute sought to protect.2
Example: All four prongs of this test are met in the example above. Note that:
- Hector violated a safety statute,
- that statutory violation injured Stacy,
- an injured leg falls within an injury that a reckless driving law is designed to protect, and
- Stacy was a member of the class that the law seeks to protect (such as an innocent motorist).
2. How is the presumption of negligence rebutted?
Negligence per se is a rebuttable presumption in California. This means that a defendant can try to counter it.
Once you – or your personal injury lawyer – establish negligence as a matter of law, the burden of proof shifts to the defendant. The defendant can then show that they were not negligent by offering evidence that:
- their violation of the law was reasonable under the circumstances,
- they were a child and acted with the same level of care as a person of similar age in similar circumstances,
- the violation was reasonable given the defendant’s disability,
- they used reasonable care in trying to comply with the law,
- compliance with the law would have involved a greater risk of harm than noncompliance, and
- they faced an emergency that was not caused by their own misconduct.3
Example: While texting 911 to report a pedestrian injured by a falling tree branch, Linda rear-ends another driver, John. Linda is presumed negligent for causing John’s injuries because texting while driving is against the law. However, Linda has a solid rebuttal of the presumption: It was reasonable in this particular case for her to violate the law because she was reporting an emergency.
3. What are the defenses in negligence per se cases?
In addition to rebutting a per se negligence presumption in California, defendants can use a defense to challenge these allegations.
Defense lawyers draw on several legal strategies, including showing that:
- the defendant did not violate a statute, law, or ordinance.
- you were not in a class of people that the law was meant to protect.
- the defendant’s violation did not cause your injuries.
3.1. The defendant did not violate a statute, law, or ordinance
Recall that negligence as a matter of law only works if there was a violation of a statute or law. This means that it is always a defense for a defendant to show that they did not break a law.
3.2. You were not in a class of people that the law was meant to protect
Also, recall that this theory only works if you were in a class of persons that the law in question wanted to protect. It is a defense, then, to show that you were not in this protected class.
Example: A doctor causes his patient Megan further complications because of serious errors made in treating her. Her husband Brian sues the doctor for medical malpractice.
Even though the doctor violated the law through medical malpractice, Brian was not in the class of people – patients – that the law was meant to protect and therefore cannot win on a negligence per se claim. However, Megan could win because she was a patient and therefore in the law’s protected class.
3.3. The defendant’s violation did not cause your injuries
You can only succeed in a negligence per se claim if you actually suffered some harm. This means it is always a defense for a defendant to show that:
- the defendant’s conduct may have violated the law, but
- this violation did not result in any harm to you.
In short, there was no causation between the breaking of a law and your injuries.
It is also a defense if a violation was not a substantial factor in causing your harm.
4. How does negligence per se differ from res ipsa loquitor?
Res ipsa loquitor is a legal doctrine used in California personal injury cases to show negligent conduct. The theory, though, is different because it uses circumstantial evidence to prove negligent conduct – not the violation of a law.
It allows a judge or jury to infer negligent conduct when:
- the facts show that an accident occurred, and
- there is no other reasonable explanation for it, but for the defendant’s acts.
Example: A small plane crashes into the ocean on a clear day. An inspection reveals no defective parts, no birds in the engine, and no other planes in the area. The plane’s only passenger was belted into his seat and the pilot was not on the radio at the time of the accident. The logical explanation is that the pilot was negligent in the crash in some way.
4.1. What are the elements of res ipsa loquitor?
To make use of res ipsa loquitur in California, you must establish three things:
- the accident or injury would not ordinarily have occurred without negligent conduct,
- the thing or incident that caused the injury was under the defendant’s exclusive control, and
- the harm was not due to anything you did.
If you show these, then the defendant can prove that they were not responsible. If the defendant cannot do this, then they will fail in defending against a claim.4
- Black’s Law Dictionary, Sixth Edition. The elements … in tort law / common law are that 1_ the defendant had a duty of care, 2) the failure of a person to act with the standard of care (he/she breached that duty to act with the standard of care), 3) the breach by the violator was the proximate cause of the plaintiff’s injuries, and 4) the injuries resulted in damages. California Evidence Code section 669. See also California Civil Jury Instructions (CACI) 418(a); See also Kuciemba v. Victory Woodworks, Inc. (2023) Civil No. S274191.
- Spriesterback v. Holland (.
- Restatement (3d) on Torts: Liability for Physical Harm. Section 15 – Excused Violations. California Evidence Code 669; see also Wildlife Alive v. Chickering (Cal. 1976) 553 P.2d 537; Nunneley v. Edgar Hotel (1950) 36 Cal.2d 493, 225 P.2d 497. See also Jones v. Awad (2019) 39 Cal.App.5th 1200; Elsner v. Uveges (2004) 34 Cal.4th 915; Cal. Serv. Station Etc. Ass’n v. Am. Home Assur. Co. (1998) 62 Cal.App.4th 1166; DiRosa v. Showa Denko K. K. (1996) 44 Cal.App.4th 799; Ramirez v. Plough, Inc. (1993) 6 Cal.4th 539; Toste v. CalPortland Construction (2016) 245 Cal.App.4th 362; Spriesterbach v. Holland (2013) 215 Cal.App.4th 255; David v. Hernandez (2014) 226 Cal.App.4th 578; Turner v. Seterus, Inc. (2018) 27 Cal.App.5th 516; Jacobs Farm/Del Cabo, Inc. (2010) 190 Cal.App.4th; Taulbee v. EJ Distribution Corp. (2019) 35 Cal.App.5th 590.
- See, for example, Barber v. Southern California Edison Co. (2022)