Authentication (law) 2230207 225227223 2008-07-12T15:54:48Z 206.209.102.135 {{EvidenceLaw}} '''Authentication''', in the [[law]] of [[evidence (law)|evidence]], is the process by which [[documentary evidence]] and other [[physical evidence]] is proven to be genuine, and not a forgery. Generally, authentication can be shown in one of two ways. First, a witness can testify as to the [[chain of custody]] through which the evidence passed from the time of the discovery up until the trial. Second, the evidence can be authenticated by the opinion of an [[expert witness]] examining the evidence to determine if it has all of the properties that it would be expected to have if it were authentic. For [[handwriting|handwritten]] documents, any person who has become familiar with the purported author's handwriting prior to the cause of action from which the trial arose can testify that a document is in that handwriting. There are several kinds of documents which have generally been judged to be [[self-authenticating documents]]. These include commercial labels, newspapers as well as other periodicals, and, finally, official publications of an arm of the government. A special category of evidence called an [[ancient document]] will be deemed authentic if it can be shown to be more than twenty years old, and found in a place and condition that a document of that age would likely be found. [[Category:Evidence]]