In The Case for Forensic Polygraph Testing in Post-Adjudication Sexual Offender Examination and Management, polygraph expert witness Ken Blackstone writes:
In a pre-adjudication setting a suspect or person of interest may be asked to take a polygraph examination as a means of assessing his or her denials about being knowledgeable, involved or even responsible for the alleged crime. A witness or informant may be asked to submit to a polygraph for the purpose of assessing the accuracy or truth of information he or she has provided. Although “victim testing” by law enforcement is barred in some states, in others an alleged victim of a crime may be asked to take a polygraph test to determine the accuracy or truth of testimony to either support the conviction of a guilty person or prevent the wrongful prosecution of an innocent person. Thus, polygraph examinations are of great importance and impact on the tested individuals and the matters to which they offer evidence. These pre-adjudication situations are all alike in that there is an “issue at hand” and they are truly voluntary.
Ken Blackstone is an expert regarding polygraph examinations. He is the author of the book Polygraph, Sex Offenders, and the Court (2011, Emerson Books ISBN 978-061-5506-80-7). www.blackstonepolygraph.com