In a civil lawsuit, documentary evidence such as photographs, letters, bills, contracts, and similar records usually have to be disclosed to the other side (typically as part of the discovery process), then properly marked as an exhibit (i.e. "Defense Exhibit 1"), and finally, authenticated or identified by a witness before being admitted into evidence at trial.
The same goes for "demonstrative" evidence such as diagrams, models, and charts, which are intended to aid the jury in understanding a witness's testimony, especially when complex concepts are at issue.
Let's look at some of the most common ways in which documents and other evidence can be authenticated and used in court by the parties in a civil case.
Methods of Authenticating Documents/Evidence
- A witness can testify that he or she is familiar with the document being introduced as an exhibit. For example, a person who was present when a contract was signed could offer testimony that he or she witnessed the signing and that the document being introduced as an exhibit appears to be that same contract. Unless the other party objects to this authentication (or the judge has more questions for the witness) the exhibit will likely make it in.
- When introducing a chart, model, or diagram, an attorney can properly lay the foundation for that evidence by asking a few questions (on the record) of the person who prepared it. Again, unless the other side objects or the judge has an issue with the evidence, it will likely be allowed in.
- The parties (and their attorneys) can agree beforehand ("stipulate") on the authenticity of a document, or the propriety of introducing demonstrative evidence.
- A non-expert witness can give an opinion as to the genuineness of the handwriting in a document, based on the witness's familiarity with the handwriting of the person who is purported to have written/signed the document.
- An expert witness can compare two handwriting samples and give an opinion as to whether the same person wrote both.
- Business records can usually be authenticated and identified by the testimony of the custodian of the records, unless the source of the information or the method of preparation of the records indicates a lack of trustworthiness.
- Self-authenticating documents usually include certified copies of public records, newspapers, and other official publications, and they do not typically require outside evidence of authenticity in order to be admitted in evidence.
What is the "Best Evidence" Rule?
In a civil lawsuit, if a document is offered into evidence as proof of its contents (one party is trying to prove that the signature on contract is in fact the defendant's, for example) the original document has to be introduced as an exhibit. If a copy or some other reproduction is offered instead of the original, the "best evidence" rule requires that the absence of the original be adequately explained. Only if the judge accepts the reasons for the absence of the original can this "secondary evidence" (a copy, in other words) be admitted into evidence.