Evidence is information that tends to prove or disprove a fact in question. Evidence may consist of documents, public records, or the testimony of witnesses. It may be an object, such as a murder weapon or a signed contract, the existence or appearance of which provides information about the fact in question. Most evidence is presented through witnesses whom a judge declares competent (mentally able) to testify. Insane people and some children may be declared incompetent.
Each party to a legal dispute presents evidence to the court. The trier of fact considers the evidence and decides the disputed facts. In a jury trial, the trier of fact is the jury. In a nonjury trial, it is the judge.
Evidence is used in other fields besides law. For example, scientists gather evidence to support theories. This article chiefly discusses court evidence.
Burden of proof
is the obligation to provide evidence, and it falls on one of the parties to a lawsuit. In a criminal case, the prosecuting attorney has the burden of proving the defendant’s guilt “beyond a reasonable doubt.” In civil trials, the party that is suing, called the plaintiff, need only prove a fact by a fair preponderance (greater weight) of the evidence.
The burden of proof may shift during a trial. For example, a plaintiff suing a defendant for injuries suffered in an automobile accident must prove that the defendant was negligent. But the burden of proof shifts to the defendant if the defendant claims that the plaintiff’s actions contributed to the accident.
Kinds of evidence.
There are two general kinds of evidence—direct evidence and circumstantial evidence. Direct evidence tends to prove a fact without the help of other evidence. For example, an eyewitness to a murder gives direct evidence by testifying that he or she saw the defendant kill the victim. Circumstantial evidence tends to prove facts that support the main fact in question, but such evidence does not tend directly to prove the main fact itself. Witnesses may give circumstantial evidence by testifying that they saw the defendant leave the murder scene. This evidence indicates that the defendant could have killed the victim, but does not prove it.
Rules
regulate the admission of evidence in court. The judge decides whether evidence is admissible under the rules. In 1975, the U.S. federal courts began to operate under uniform rules. Many state rules of evidence closely follow the federal rules, but a state court is not required to follow federal rules. Thus rules of evidence may vary from state to state.
One type of evidence that generally is not admitted is hearsay. Such evidence is testimony in which a witness tells the court what he or she heard others say, rather than what the witness knows from firsthand experience.
Relevancy.
Evidence must be relevant to be admitted in court—that is, it must relate to and help resolve a significant question in a case. Evidence that seems relevant may be excluded because it might prejudice or mislead a jury. For example, evidence that a defendant has previously committed crimes is not ordinarily admitted.
Privilege
is the right to withhold evidence to protect an important interest or relationship. The U.S. Constitution provides some privileges. For example, accused people cannot be forced to give evidence against themselves at a criminal trial. Other privileges include the right not to reveal confidential communication between husbands and wives, attorneys and clients, or priests and the people whose confessions they hear. The federal government has also claimed privilege on the grounds of national security or defense.
Presumptions.
If evidence about a fact is lacking, a rule of law may state that the fact is proved by other facts. Such a statement is called a presumption. For example, proof that a person has been missing for at least seven years may result in the presumption that he or she is dead.
See also Crime scene investigation; DNA fingerprinting; Forensic pathology; Forensic science; Trial; Witness.
