In forensic science, questioned document examination (QDE) is the examination of documents potentially disputed in a court of law. Its primary purpose is to provide evidence about a suspicious or questionable document using scientific processes and methods. Evidence might include alterations, the chain of possession, damage to the document, forgery, origin, authenticity, or other questions that come up when a document is challenged in court.
Many QD examinations involve a comparison of the questioned document, or components of the document, to a set of known standards. The most common type of examination involves handwriting wherein the examiner tries to address concerns about potential authorship.
A document examiner is often asked to determine if a questioned item originated from the same source as the known item(s), then present their opinion on the matter in court as an expert witness. Other common tasks include determining what has happened to a document, determining when a document was produced, or deciphering information on the document that has been obscured, obliterated, or erased.
The discipline is known by many names including 'forensic document examination', 'document examination', 'diplomatics', 'handwriting examination', or sometimes 'handwriting analysis', although the latter term is not often used as it may be confused with graphology. Likewise a forensic document examiner (FDE) is not to be confused with a graphologist, and vice versa.
Many FDEs receive extensive training in all of the aspects of the discipline. As a result, they are competent to address a wide variety of questions about document evidence. However, this "broad specialization" approach has not been universally adopted.
In some locales, a clear distinction is made between the terms 'forensic document examiner' and a 'forensic handwriting expert/examiner'. In such cases, the former term refers to examiners who focus on non-handwriting examination types while the latter refers to those trained exclusively to do handwriting examinations. Even in places where the more general meaning is common, such as North America or Australia, there are many individuals who have specialized training only in relatively limited areas. As the terminology varies from jurisdiction to jurisdiction, it is important to clarify the meaning of the title used by any individual professing to be a "forensic document examiner".
A forensic document examiner is intimately linked to the legal system as a forensic scientist. Forensic science is the application of science to address issues under consideration in the legal system. FDEs examine items (documents) that form part of a case that may or may not come before a court of law.