Proof of the Breach in Negligence Cases (Including Res Ipsa Loquitur)

The plaintiff has the burden of proving each of the essential elements of a cause of action for negligence. The term burden of proof is used in two senses. The first is often called the burden of going forward with evidence and it means that if the plaintiff does not, in the first instance, introduce evidence on each element which is sufficient to warrant a finding in his favor, he will lose his case at the hands of the court (by nonsuit, directed verdict, or the like). If the plaintiff has introduced sufficient evidence (before he rests his case) he has made out a prima facie case and is entitled to go to the jury. His burden of going forward is met and drops out of the case. Thus the burden of going forward with evidence is applied always by the court, never by the jury. Burden of proof in the other sense does not come into play until a case is finally submitted to the jury (or court as trier of facts) for determination. In that process the trier may find the evidence on any given issue in equipoise--or his mind may be in equipoise as to the evaluation of conduct as negligent or careful. In that event, he who has the burden of proof in this sense of the risk of non-persuasion, must fail. This burden is applied by the trier of facts, and in a jury case the charge must define this burden and tell the jury how to apply it. In civil cases generally the plaintiff is entitled to prevail if the jury finds that more probably than not the facts are as he alleges. This does not mean all the facts (e.g., every item of negligence) but so many of them as constitute the essential elements of his cause of action as defined by the court in its charge