In criminal trials, the prosecution has to prove each element necessary to its case beyond a reasonable doubt. In civil trials, on the other hand, a party has the burden only of proving affirmative contentions by a preponderance of the evidence. Thus the plaintiff must offer some proof of each of the elements that combine to constitute the defendant's alleged wrong (see procedure), while the defendant must prove his or her affirmative defenses, e.g., in a suit for negligence, that the plaintiff's own negligence contributed to the injury.
Satisfying the burden of proof requires the prosecutor or the plaintiff to present evidence first. At the close of this presentation the criminal or civil defendant may move for acquittal or a nonsuit if admissible evidence supporting necessary contentions has not been offered. Proof may be dispensed with when an adversary formally admits a fact either in the pleadings or in court, or when the court may take judicial notice of the fact, i.e., when the fact is universally known or is easily ascertainable by the judge beyond reasonable dispute.
In recent years the problems of procuring evidence have been eased somewhat by the introduction of broader discovery (i.e., disclosure) rules. In civil cases, these rules compel each party to a suit to allow the other to have access to its witnesses and to certain types of evidence before the trial. In criminal cases, the judge has the discretionary power to order discovery; in any event, the prosecutor must release all exculpatory evidence on request.
Allegedly damaging errors in the admission of evidence are reviewable on appeal if an objection was made during the trial. In their final summing up, the attorneys may make any assertion that is supported to some degree by evidence. British judges and U.S. federal and, in some jurisdictions, state judges are permitted to comment on the credibility of the witnesses and the weight of the evidence. However, the judge must tell the jury that they are not bound by his or her remarks.
See also verdict.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.