Negligence

In a negligence suit, the plaintiff has the burden of proving that the defendant did not act as a reasonable person would have acted under the circumstances. The court will instruct the jury as to the standard of conduct required of the defendant. For example, a defendant sued for negligent driving is judged according to how a reasonable person would have driven in the same circumstances. A plaintiff has a variety of means of proving that a defendant did not act as the hypothetical reasonable person would have acted. The plaintiff can show that the defendant violated a statute designed to protect against the type of injury that occurred to the plaintiff. Also, a plaintiff might introduce expert witnesses, evidence of a customary practice, or CIRCUMSTANTIAL EVIDENCE.

Statutes Federal and state statutes, municipal ordinances, and administrative regulations govern all kinds of conduct and frequently impose standards of conduct to be observed. For example, the law prohibits driving through a red traffic light at an intersection. A plaintiff injured by a defendant who ignored a red light can introduce the defendant's violation of the statute as evidence that the defendant acted negligently. However, a plaintiff's evidence that the defendant violated a statute does not always establish that the defendant acted unreasonably. The statute that was violated must have been intended to protect against the particular hazard or type of harm that caused injury to the plaintiff.

Sometimes physical circumstances beyond a person's control can excuse the violation of a statute, such as when the headlights of a vehicle suddenly fail, or when a driver swerves into oncoming traffic to avoid a child who darted into the street. To excuse the violation, the defendant must establish that, in failing to comply with the statute, she acted as a reasonable person would have acted.

In many jurisdictions the violation of a statute, regulation, or ordinance enacted to protect against the harm that resulted to the plaintiff is considered negligence per se. Unless the defendant presents evidence excusing the violation of the statute, the defendant's negligence is conclusively established. In some jurisdictions a defendant's violation of a statute is merely evidence that the defendant acted negligently.

Experts Often a plaintiff will need an expert witness to establish that the defendant did not adhere to the conduct expected of a reasonably prudent person in the defendant's circumstances. A juror may be unable to determine from his own experience, for example, if the medicine prescribed by a physician was reasonably appropriate for a patient's illness. Experts may provide the jury with information beyond the common knowledge of jurors, such as scientific theories, data, tests, and experiments. Also, in cases involving professionals such as physicians, experts establish the standard of care expected of the professional. In the above example, the patient might have a physician offer EXPERT TESTIMONY regarding the medication that a reasonably prudent physician would have prescribed for the patient's illness.

Custom Evidence of the usual and customary conduct or practice of others under similar circumstances can be admitted to establish the proper standard of reasonable conduct. Like the evidence provided by expert witnesses, evidence of custom and habit is usually used in cases where the nature of the alleged negligence is beyond the common knowledge of the jurors. Often such evidence is presented in cases alleging negligence in some business activity. For example, a plaintiff suing the manufacturer of a punch press that injured her might present evidence that all other manufacturers of punch presses incorporate a certain safety device that would have prevented the injury.

A plaintiff's evidence of conformity or nonconformity with a customary practice does not establish whether the defendant was negligent; the jury decides whether a reasonably prudent person would have done more or less than is customary.

Circumstantial Evidence Sometimes a plaintiff has no direct evidence of how the defendant acted and must attempt to prove his case through circumstantial evidence. Of course, any fact in a lawsuit may be proved by circumstantial evidence. Skid marks can establish the speed a car was traveling prior to a collision, a person's appearance can circumstantially prove his or her age, etc. Sometimes a plaintiff in a negligence lawsuit must prove his entire case by circumstantial evidence. Suppose a plaintiff's shoulder is severely injured during an operation to remove his tonsils. The plaintiff, who was unconscious during the operation, sues the doctor in charge of the operation for negligence, even though he has no idea how the injury actually occurred. The doctor refuses to say how the injury occurred, so the plaintiff will have to prove his case by circumstantial evidence.

In cases such as this, the doctrine of RES IPSA LOQUITUR (the thing speaks for itself) is invoked. Res ipsa loquitor allows a plaintiff to prove negligence on the theory that his injury could not have occurred in the absence of the defendant's negligence. The plaintiff must establish that the injury was caused by an instrumentality or condition that was under the defendant's exclusive management or control and that the plaintiff's injury would not have occurred if the defendant had acted with reasonable care. Thus, in the above example, the plaintiff can use res ipsa loquitor to prove that the doctor negligently injured his shoulder.