Any document whose validity has been questioned through legal means is considered a disputed or questioned document. The main function of the questioned or forensic document examiner is to determine, through various scientific and proven procedures, if the document in question was authored and/or executed by the individual(s) legally bound by the document.
To determine the truth regarding the legitimacy of the questioned document(s), the Forensic Examiner follows tried and accepted methods of determining the authenticity of a document. A laboratory, either belonging to the Forensic Examiner or an outside company, provides access to the most applicable technology used in determining whether a document is authentic.
All Questioned/Forensic Examiners presenting evidence in court must follow the correct protocol standards as required by the court in which the case is heard. Following the correct protocols (Daubert, Frye, etc), and ability to demonstrate sufficient skill, knowledge, training, education or experience ensures admissibility of expert witness testimony during United States federal legal proceedings.