NOTE: For suspected employee thefts, see the requirements of the Employee Polygraph Protection Act (EPPA) of 1988 - click link below
Before hiring a polygraph examiner always find out about their professional credentials and experience. Find out if they have graduated from a polygraph school accredited by the American Polygraph Association or recognized by the American Association of Police Polygraphists.
- Ask how long they have been a polygraph examiner and how many polygraph examinations they have administered because experience is important. - Find out how many professional polygraph associations they belong to (at a minimum they should belong to a state and a national association).
- Ask if they are qualified as an expert polygraph witness in state and federal courts.
- Find out how often they attend continuing education courses (they should attend at least one seminar per year to stay current) and find out if they are licensed. In many states (Georgia is one of them) polygraph is not regulated and a license is not required. That means all one has to do is purchase a polygraph instrument and call themselves a polygraphist to be in business. If they are experienced and truly professional, they will want you to know about their qualifications and will gladly provide you with this information on their website or in writing. If this information is not readily available - Ask!
The last thing you need is to spend your money on an inaccurate polygraph test. Test results that are inaccurate can cost you a lot more than your money. It can cost you your job, your relationship, your reputation, or in criminal matters.... harm your defense! Always compare polygraph examiner credentials and experiences before choosing a polygraphist.
Never Use a VOICE STRESS Based Lie Detector!
As you search the internet for polygraphists you may find individuals who state they conduct "voice polygraphs". These so called voice polygraphs are not polygraphs at all. What they are is a device called Computerized Voice Stress Analyzers (CVSA or VSA machines) that only measures changes in a person's voice. Those promoting the CVSA will tell you that there are no inclusive results such as with the polygraph. All of this is great marketing, but the fact is the CVSA has been researched by the U.S. Government and others and they found CVSA to be highly unreliable - only 52% accurate. That's about the same odds as flipping a coin. Voice stress people will often tell you they can conduct a CVSA over the phone. How does the client know the person who says they can do this is doing anything at all on the other end of the line? - So beware.
The American Polygraph Association (APA) has posted a number of studies relative to the inaccuracy of voice stress. Please see the following APA webpage: APA Voice Stress Article
Donald J. Imbordino
Certified by the American Association of Police Polygraphists and recipient of certification in advanced training by the American Polygraph Association
A polygraph examination (credibility assessment) is a scientific test that collects physiological data from a person with the purpose of identifying reactions associated with dishonesty. At least three systems in the human body are recorded during a polygraph examination. Respiratory activity is monitored by placing rubber tubes across the examinee's upper portion and abdominal portion of the chest. Electro-dermal (sweat gland) activity is recorded by placing two small attachments on the fingers or palm of the hand. And cardiovascular activity (blood pressure and pulse) is collected by a blood pressure cuff or similar device. It is important to note that a polygraph does not include the analysis of physiology associated with the voice. Instruments that claim to record voice or psychological stress are not polygraphs and have not been shown to have scientific support.
A professional polygraph examination has three phases: a pretest phase, an in- test phase, and a post-test phase, which includes test data analysis. A typical polygraph examination will last at least two hours, and sometimes longer.
Pretest ~ In the pretest phase, the polygraph examiner will complete required paperwork and talk with the examinee about the test. During this period the examiner will discuss and review the questions to be asked, discuss the issue being tested on, and familiarize the examinee with the testing procedure and the polygraph instrument.
In-Test ~ The in-test (chart collection) phase takes place in a quiet room with no one else present to distract the examinee. The polygraphist will attach sensors to the person and then ask previously discussed questions designed to be answered yes or no. Data is collected via the sensors and are recorded in the form of polygraph charts. Polygraph examiners may use conventional instruments, sometimes referred to as analog instruments, or the more modern computerized polygraph instruments.
Post-Test ~ Following the in-test phase, the polygraphist will analyze the data on the charts and render an opinion as to the truthfulness of the person taking the exam. The examiner, when appropriate, will offer the examinee an opportunity to explain physiological reactions in relation to one or more questions asked during the polygraph examination.
Polygraph examinations are used to protect the public, to verify the truth, to identify the innocent, and determine deception to help identify the guilty. Polygraphs are most commonly used for criminal and civil matters, government and law enforcement pre-employment screening, homeland security, commercial theft investigations and to monitor convicted sex offenders being supervised by probation and parole, and while under treatment. Private parties also request polygraph examinations to help resolve personal matters.
Polygraph exams are used by federal, state and local law enforcement agencies, U.S. and district attorneys, public defenders, lawyers, private individuals, and parole and probation departments worldwide. Private and public companies also use polygraph examinations when authorized under the Employee Polygraph Protection Act of 1988 (EPPA) for acts of theft, sabotage or espionage.
The easiest and most effective way to make sure you are retaining a qualified polygraph examiner is to ask if he or she is a member of the American Polygraph Association (APA), the American Association of Police Polygraphists (AAPP) or one of its affiliates. APA and AAPP professional examiners are required to have extensive training at an AAPP or APA approved polygraph school and are required to continually study the latest truth detection technology and techniques. The APA and AAPP also govern the conduct of its members by requiring adherence to a code of ethics and a set of established standards of practice. Both polygraph associations offer advanced professional certification based on the examiner's level of continuing education.
While the polygraph technique is highly accurate, errors can occur. Polygraph errors may be caused by the examiner's failure to properly prepare the examinee for the examination or by a misinterpreting the physiological data collected during the polygraph examination. Errors are usually referred to as either false positives or false negatives. A false positive occurs when a truthful examinee is reported as being deceptive. A false negative occurs when a deceptive examinee is reported as truthful. Since it is recognized that any error is damaging, examiners utilize a variety of procedures to identify the presence of factors which may cause false responses, and to insure an unbiased review of the polygraph charts.
An inconclusive or no opinion result simply means that insufficient data is available for the examiner to render a definitive opinion of deception indicated (DI) or no deception indicated (NDI). In such cases a second examination is usually conducted in an effort to arrive at a decision. The classification of a polygraph examination as "inconclusive" protects the examinee from being falsely identified as deceptive when inadequate data is collected. Critics of polygraph have wrongly classified inconclusive test results as errors. In actuality, a determination of inclusive is made to avoid errors in identifying truthfulness or deception of an examinee.
No. While a person's heart beat and respiration rate may increase when he or she is nervous, a qualified examiner understands this and will take it into consideration when evaluating an examinee's response. Unlike general nervous tension, an examinee's reaction to deceptive responses is highly specific. An examiner mitigates a nervous response by reviewing the questions with the examinee and through an acquaintance or "practice test" prior to the exam.
While the polygraph technique is not infallible, research clearly indicates that when administered by a competent examiner the polygraph test is the most accurate means available to determine truth and deception. Since 1980, a compendium of research studies - encompassing 80 research projects involving 6,380 polygraph examinations and 12 studies of the validity of field examinations following 2,174 field examinations, indicate an average accuracy rate of 98%.
It is important for the public be aware the National Academies of Science (NAS) did not conduct any new or original laboratory or field research to prepare its report. The NAS review of polygraph studies was limited to its use in personnel security screening only, which included a review of just 57 of 1,000 research studies available. APA & AAPP agree with the panel's important conclusion that although there may be alternative techniques for detecting deception, none of these alternatives outperforms polygraph, nor do any of them show promise of supplanting polygraph in the near future.
Polygraph results (or psychophysiological detection of deception examinations) are admissible in some federal circuits and some states. More often, such evidence is admissible where the parties have agreed to their admissibility before the examination is given, under terms of a stipulation. Some jurisdictions have absolute bans on admissibility of polygraph results as evidence and even the suggestion that a polygraph examination is involved is sufficient to cause a retrial. The United States Supreme Court has yet to rule on the issue of admissibility, so the rules in federal circuits vary considerably. The Supreme Court has said, in passing, that polygraph examinations raise the issue of Fifth Amendment protection, [Schmerber v. California, 86 S. Ct. 1826 (l966).] The Supreme Court has also held that a Miranda warning before a polygraph examination is sufficient to allow admissibility of a confession that follows an examination, [Wyrick v. Fields, 103 S. Ct. 394 (1982).] In 1993, the Supreme Court removed the restrictive requirements of the 1923 Frye decision on scientific evidence and said Rule 702 requirements were sufficient, [Daubert v. Mettell Dow Pharmaceutcals, 113 S.ct. 2786.]Daubert did not involve lie detection, per se, as an issue, as Frye did, but it had a profound effect on admissibility of polygraph results as evidence, when proffered by the defendants under the principles embodied in the Federal Rules of Evidence expressed in Daubert, see [United States v. Posado (5th Cir. 1995) WL 368417.] Some circuits already have specific rules for admissibility, such as the 11th Circuit which specifies what must be done for polygraph results to be admitted over objection, or under stipulation, [United States v. Piccinonna 885 F.2d 1529 (11th Cir. 1989).] Other circuits have left the decision to the discretion of the trial judge. The rules that states and federal circuits generally follow in stipulated admissibility were established in [State v. Valdez, 371 P.2d 894 (Arizona, 1962).] The rules followed when polygraph results are admitted over objection of opposing counsel usually cite [State v. Dorsey, 539 P.2d 204 (New Mexico, 1975).] Primarily because of Daubert, as well as the impact the other cited cases have had, polygraph examination admissibility is changing in many states. Many appeals, based on the exclusion of polygraph evidence at trial are now under review by appellate courts.
Representative case citations are provided for reference:
Clements v. State, 474 So.2d 695 (1984).
Green v. Am. Cast Iron, 464 so.2d 294 (1984).
State v. Valdez, 91 Ariz.. 274, 371, P.2d 894 (1962).
State v. Molina, 117 Ariz. 4541 573 P.2d 528 (App.1977).
Hays v. State, 767 S.W.2d 525 (1989).
People v. Houser, 85 Cal.App.2d 686, 193 P.2d 937 (1948)
Robinson v. Wilson, 44 Cal.App.3d 92, 118 Cal.Rptr. 569 (1974).
Witherspoon v. Superior Court, 133 Cal.App.3rd 24 (1982)
Williams v. State, 378 A.2nd 117 (1977).
State v. Chambers, 240 Ga. 76, 239 SE.2d 324 (1977).
Miller v. State, 380 S.E.2d 690 (1989).
State v. Fain, 774 P.2d 252 (1989).
Barnes v. State, 537 N.E.2d 489 (1989).
Davidson v. State, 558 N.E.2d 1077 (1990).
State v. McNamara, 104 N.W.2d 568 (1960).
Haldeman v. Total Petroleum, 376 N.W.2d 98 (1985).
State v. Roach, 570P.2d 1082 (1978).
Corbett v. State, 584 P.2d 704 (1978).
State v. McDavitt, 297 A.2d 849 (1972).
State v. McMahon 524 A.2d 1348 (1986).
State v. Dorsey, 539 P.2ed 204 (1975).
State v. Newman, 409 N.W.2d 79 (1987).
Moss v. Nationwide, 493 N.E.2d 969 (1985).
State v. Souel, 372 N.E.2d 1318 (1978).
State v. Jenkins, 523 P.2d 1232 (1974).
State v. Rebetevano, 681 P.2d 1265 (1984).
State v. Grigsby, 647 P.2d 6 (1982).
Cullin v. State, 565 P.2d 445 (1977).
Source: American Polygraph Association