Negligence per se is a legal doctrine by which defendants are presumed to have acted negligently if they violate a statute or ordinance and thereby injure someone. The theory arises in the context of personal injury lawsuits. While all states follow the general premise of the doctrine, states differ slightly in their application.
Note that negligence per se is a rebuttable presumption. This means that once a plaintiff establishes it, a defendant can counter or challenge it. A defendant can do this in several ways. For example, the defendant can show that his/her violation of the law was reasonable under the circumstances.
In addition, a defendant can raise a defense to contest a per se negligence allegation. Some defenses include that the:
- defendant did not commit a violation of the statute, ordinance, or rule at issue,
- the plaintiff was not in a class of people that the statute sought to protect, and
- the defendant’s violation did not cause the plaintiff’s injuries.
California applies the negligence per se theory. Evidence Code 669 is the California statute that outlines the doctrine.
In this article, our personal injury attorneys will answer the following questions:
- 1. What is the legal definition of negligence per se?
- 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?
- 5. What is the law in California?
1. What is the legal definition of negligence per se?
Negligence per se is a theory in personal injury cases that a person is presumed to have acted negligently if he/she injures someone in the course of violating a statute.
A plaintiff has to prove the following to recover damages in a personal injury claim:
- the defendant acted with negligence, and
- this negligence was a substantial factor in causing harm to the plaintiff.
Ordinary negligence cases occur when a defendant:
- does something that a reasonable person would not due under the circumstances, or
- fails to do something that a reasonable person (person of ordinary prudence) would do in the same situation.1
Negligence per se (a.k.a. negligence “as a matter of law”) is a theory that makes it easier for a victim 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. The driver of the other vehicle, Stacy, suffers a broken leg. After police arrive at the scene of the accident, they investigate and later cite Hector for reckless driving for greatly exceeding the speed limit. The state has a specific statute that prohibits such driving precisely because it causes automobile accidents. He pleads guilty to the charge.
Stacy later files a personal injury lawsuit against Hector for compensation for her injuries.
To win at trial, Stacy must establish that Hector was negligent in driving his motor vehicle. She can do this under a per se negligence theory. Since Hector violated his statutory duty not to commit reckless driving, he is presumed to have acted negligently in his particular case. That in itself is sufficient evidence of negligence. Stacy does not have to make a separate showing that the defendant’s conduct was unreasonable.
In most states, a defendant is presumed negligent as a matter of law when:
- he/she violated a statute, ordinance, or regulation,
- the violation caused death or injury to a person or property,
- the death or injury was the type of harm that the statute was designed to prevent, and
- the person who suffered the death or injury was 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 (i.e., an innocent motorist).
2. How is the presumption of negligence rebutted?
Negligence per se is a rebuttable presumption. This means that a defendant can try to counter it.
Once a plaintiff establishes negligence as a matter of law, the burden of proof shifts to the defendant. The defendant can then show that he or she was not negligent.
A defendant can do this by offering evidence that:
- his/her violation of the law was reasonable under the circumstances,
- the violation was reasonable given the defendant’s age or disability,
- he/she 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
- he/she faced an emergency that was not caused by his/her own misconduct.3
Example: Linda is using her cell phone while driving. She rear-ends another driver, John. John suffers neck injures because of the collision.
John eventually files a lawsuit against Linda to recover damages from the injury. The state they live in has a statute that says it is illegal for a motorist to use a handheld device while operating a vehicle.
At trial, John introduces evidence of this statute to show that Linda was negligent as a matter of law. He alleges that she was negligent because she was using her cell phone while driving, and thus, violated the law.
Linda can then rebut the presumption. She does so by showing that she was on her phone to report an emergency. She had just observed an accident and noticed a badly hurt pedestrian. Here, Linda’s rebuttal works because it shows that she tried to comply with the law, but she had to violate it because of an emergency. Her violation was reasonable under the circumstances.
3. What are the defenses in negligence per se cases?
In addition to rebutting a per se negligence presumption, defendants can use a defense to challenge these allegations.
Defense lawyers draw on several legal strategies to challenge these charges. These include showing that:
- the defendant did not violate a statute, law, or ordinance.
- the plaintiff was not in a class of people that the law wanted to protect.
- the defendant’s violation did not cause the plaintiff’s injuries.
3.1. No violation of a statute
Recall that negligence as a matter of law only works if a person violated a statute or law. This means that it is always a defense for a defendant to show that he/she did not break a law.
3.2. Plaintiff not in a protected class
Also recall that this theory only works if the plaintiff was in a class of persons that the law in question wanted to protect. It is a defense, then, to show that the plaintiff was not in this protected class.
Example: Brian and Megan are a married couple. Brian rushes Megan to the ER because of an emergency medical condition. An ER doctor causes Megan further complications because of errors made in treating her. The errors are in clear violation of a state medical malpractice law (which seeks to protect injured patients). Brian files a lawsuit against the doctor for medical malpractice.
Here, the doctor can successfully challenge any negligent per se claim. Granted, the physician may have violated the law, but Brian was not in the class of people that the law wanted to protect. He was not a patient or a person experiencing emergency medical needs.
Note, though, that Megan could make a negligent per se claim. She was in a protected class because she was a patient and the law sought to protect people in need of medical care.
3.3. Defendant’s violation did not cause an injury
A plaintiff can only succeed in a negligence per se claim if he/she actually suffered some harm. This means it is always a defense for a defendant to show that:
- he/she may have violated the law, but
- this violation did not result in any harm to the plaintiff.
It is also a defense if a violation was not a substantial factor in causing the plaintiff’s harm.
4. How does negligence per se differ from res ipsa loquitor?
Res ipsa loquitor is a legal doctrine used in 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 for the crash in some way.
To make use of res ipsa loquitur, the plaintiff 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 the plaintiff did.
If a plaintiff shows these, then the defendant can prove that he/she was not responsible. If the defendant cannot do this, then he/she will fail in defending against a claim.
5. What is the law in California?
California law applies the doctrine of negligence per se and follows the rules outlined above.
Evidence Code 669 is the California statute that:
- sets forth the same four-part test as outlined above (in section 1), and
- applies it to these cases to establish negligence per se.4
State law also says that a defendant can rebut a presumption by showing the trier of fact (the court) that:
- he/she acted as a reasonable person would under similar circumstances, or
- the accused was a child and acted with the same level of care as a person of similar age.5
- 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.
- Smith v. Trans-world Drilling Co., 772 F.2d 157 (U.S. Court of Appeals, 5th Cir. 1985). See also Vanderwerf v. Smithklinebeecham Corp., 414 F.Supp.2d 1023 (2006).
- Restatement (3d) on Torts: Liability for Physical Harm. Section 15 – Excused Violations.
- California Evidence Code section 669. See also California Civil Jury Instructions (CACI) 418(a); and, Spriesterbach v. Holland (2013) 215 Cal.App.4th 255.
- California Evidence Code 669; see also Wildlife Alive v. Chickering, 18 Cal.3d 190, 132 Cal.Rptr. 377, 553 P.2d 537 (1976); Nunneley v. Edgar Hotel, 36 Cal.2d 493, 225 P.2d 497 (Cal. Supreme Court, 1950).