Define authentication. Explain why evidence must be authenticated. How is evidence authenticated?

Authentication is the process of establishing the genuineness of an item that is to be introduced as evidence in a trial.
At trial, an attorney must lay the proper foundation for the introduction of certain evidence, such as documents, exhibits, and other objects, and must demonstrate to the court that the evidence is what the attorney claims. The authentication requirement relates to relevance, because something offered in evidence becomes relevant to the case only if it is authentic, or genuine. Also, the rules of evidence require authentication because certain types of evidence, such as exhibits and objects, cannot be cross-examined by opposing counsel, as witnesses can, yet such evidence may have a significant effect on the jury. The authentication requirement provides a safeguard against the introduction of nonverified evidence that may strongly influence the outcome of the case. Commonly, evidence is authenticated by the testimony of witnesses. The Federal Rules of Evidence provide for the self-authentication of specific types of evidence. In other words, certain documents or records need not be authenticated by testimony. Certified copies of public records, for example, are automatically deemed authentic. Other self-authenticating evidentiary documents include official publications (such as a report issued by the federal Environmental Protection Agency), documents containing a notary public's seal or the seal of a public official, and manufacturers' trademarks or labels.