Evidence contained in or on documents can be a form of real evidence. For example, a contract offered to prove the terms it contains is both documentary and real evidence. When a party offers a document into evidence, the party must authenticate it the same way as any other real evidence, either by a witness who can identify the document or by witnesses who can establish a chain of custody for the document.
When people deal with documentary evidence, it is a good idea to consider these four potential pitfalls:
- Parol evidence
- Best evidence
The parol evidence rule prohibits the admission of certain evidence concerning the terms of a written agreement. Parol evidence is usually considered an issue of substantive law, rather than a pure evidentiary matter.
A party can authenticate documentary evidence in much the same way as it can authenticate other real evidence. Also, some kinds of documents are essentially self-authenticating under the FRE. Some of these are:
- Acknowledged documents to prove the acknowledgment
- Certain commercial paper and related documents
- Certificates of the custodians of business records
- Certified copies of public records
- Official documents
- Trade inscriptions
The best evidence rule states that when the contents of a written document are offered in evidence, the court will not accept a copy or other proof of the document's content in place of the original document unless an adequate explanation is offered for the absence of the original. The FRE permits the use of mechanically reproduced documents unless one of the parties has raised a genuine question about the accuracy of the copy or can somehow show that its use would be unfair. Also under the FRE, summaries or compilations of lengthy documents may be received into evidence as long as the other parties have made the originals available for examination.