Admissible Evidence

In a criminal case, evidence is important to both the prosecution and defense. When evidence is entered before the judge or jury, it is important that it is relevant, reliable and not prejudiced. If the evidence meets all of these requirements, it is referred to as admissible evidence.

In order for evidence to be considered relevant, it must prove or disprove a point that is being made by either party. However, if the evidence causes the judge or jury to look unfavorably at the party it is used against for a reason unrelated to the case, the judge may find that it is not admissible.

For evidence to be considered reliable, the party entering the evidence must be able to prove that the source of the evidence is itself reliable. For example, if witness testimony is presented as evidence, the side that introduces the evidence must show that the witness is credible and has knowledge about the subject matter that he or she is testifying about.

Because hearsay is information that is gathered second hand, it is considered unreliable and thus inadmissible in court. The trial judge must ensure that unreliable testimonies are excluded from the case.

The United States Supreme Court first laid out the reliability requirements for expert witnesses in Daubert v. Merrell Dow Pharmaceuticals, Inc. The Court decided on four factors that trial courts may look at when evaluating the expert witness’s reliability. They are: (1) whether the evidence has been subject to scientific testing and, if so, what methodology was used; (2) whether the evidence has been reviewed by peers or a scientific publication; (3)what is the known potential rate of error; (4) is the evidence generally accepted in the scientific community.

If documents are entered as evidence, the side that presents the evidence must be able to prove that it is authentic and must be able to show the chain of custody from the original document creator to the person who now holds it.

There are other factors that may render evidence inadmissible in court. For example, if the police officer investigating the case seized evidence without a search warrant or probable cause, it may not be used in court.