ination and what he knows about the polygraph and how it works. The examiner will then
ask the examinee if he understands that to take a polygraph examination it requires his
complete cooperation. “Obviously, if you are telling me the truth, you would want to coop-
erate. If you are lying, you would not. Therefore, if you deliberately do not cooperate, it will
indicate that you are not truthful, and I will report you as deceptive.” The examinee is then
given the following “Agreement for Cooperation” form to read and sign:
Keystone Intelligence Network, Inc.
1704 Locust Street, Philadelphia, PA 19103 www.keystone intelligence.com 215 545 1111
Agreement of Cooperation
• I understand and agree that the polygraph procedure requires my total cooperation.
• I agree that a truthful person would offer full cooperation to the procedure and that a
person who is lying would be uncooperative.
• I further agree that as in any scientific procedure, deliberate attempts to defeat the
purpose of the assessment are counterproductive and in itself a sign of deception.
• Therefore I accept that any lack of full cooperation on my part will be considered to be
the behavior of a deceptive individual and the grounds for the examiner to report the
results as same.
Signed by Examinee
Date
Witnessed by Examiner
Date
The examinee is then asked if he is aware that everyone cannot take a polygraph test.
A small percentage of the population cannot be tested because when they lie, the
21. THE INSTRUMENTAL DETECTION OF DECEPTION: POLYGRAPH
307
physiological changes that occur are not discernible to the polygraph. To ensure that the
examinee is not in this category, he is told that he will be given a test to make sure that if
he lies, the polygraph shows that he is deceptive, and just as important, when he tells the
truth, the polygraph shows that he is truthful. A demonstration test, also known as an
acquaintance test, is then administered, and the examinee is made aware of the fact that
he is testable.
All of the test questions are then reviewed with the examinee. The examiner makes sure
that the meaning of each question is shared by both the examiner and examinee by asking
the examinee to explain what each question means. This reduces the possibility of an
examinee rationalizing or personally coding an important question.
IZCT Single Issue
1. IRRELEVANT
Is today Sunday? (Incorrect day)
NO
2. SYMPTOMATIC
Do you understand I will only ask the questions I
YES
reviewed?
3. SACRIFICE
Do you intend to deliberately lie to any test question?
NO
4. IRRELEVANT
Is today Monday? (Correct day)
YES
5. COMPARISON
During the 1st 24 years of your life, can you remember
NO
stealing anything?
6. RELEVANT
Did you take that missing deposit?
NO
7. IRRELEVANT
Right now are you in the U.S.?
YES
8. COMPARISON
In your entire life, did you steal anything from a job?
NO
9. RELEVANT
Regarding that missing deposit, did you take it?
NO
10. IRRELEVANT
Right now are you in Switzerland?
NO
11. COMPARISION
During the 1st 24 years of your life, did you ever steal
NO
from someone who trusted you?
12. RELEVANT
Were you the person that took that missing deposit?
NO
13. COUNTERMEASURE
Have you deliberately done anything to try to beat this
NO
test?
A modification of the Backster S-K-Y using the IZCT-SKY is as follows:
IZCT Single Issue
1. IRRELEVANT
Is today Sunday? (Incorrect day)
NO
2. SYMPTOMATIC
Do you understand I will only ask the questions I
YES
reviewed?
3. SACRIFICE
Do you intend to deliberately lie to any test question?
NO
4. IRRELEVANT
Is today Monday? (Correct day)
YES
5. COMPARISON (S)
Regarding that missing deposit, do you suspect anyone
NO
in particular of taking it?
6. RELEVANT (K)
Regarding that missing deposit, do you know for sure
NO
who took it?
7. IRRELEVANT
Right now are you in the U.S.?
YES
8. COMPARISON
In your entire life, did you steal anything from a job?
NO
9. RELEVANT (Y)
Did you take that missing deposit?
NO
10. IRRELEVANT
Right now are you in Switzerland?
NO
308
21. THE INSTRUMENTAL DETECTION OF DECEPTION: POLYGRAPH
11. COMPARISION
During the 1st 24 years of your life, did you ever steal
NO
from someone who trusted you?
12. RELEVANT
Did you leave the store with any of that missing money
NO
in your possession?
13. COUNTERMEASURE
Have you deliberately done anything to try to beat this
NO
test?
A modification of the Matte Quadra-Trak using the IZCT-2 is:
1. IRRELEVANT
Is today Sunday? (Incorrect day)
NO
2. SYMPTOMATIC
Do you understand I will only ask the questions I
YES
reviewed?
3. SACRIFICE
Do you intend to deliberately lie to any test question?
NO
4. IRRELEVANT
Is today Monday? (Correct day)
YES
5. COMPARISON
During the 1st 54 years of your life, can you remember
NO
lying to get out of trouble?
6. RELEVANT
Did you masturbate in front of your granddaughter?
NO
7. IRRELEVANT
Right now are you in the U.S.?
YES
8. COMPARISON
In your entire life, did you ever lie about a sexual matter?
NO
9. RELEVANT
Regarding your granddaughter, did you masturbate in
NO
front of her?
10. IRRELEVANT
Right now are you in Switzerland?
NO
11. COMPARISION
Are you afraid I will make an error in this test,
NO
concerning whether you masturbated in front of your
granddaughter?
12. RELEVANT
Are you hoping I will make an error in this test,
NO
concerning whether you masturbated in front of your
granddaughter?
13. COUNTERMEASURE
Have you deliberately done anything to try to beat this
NO
test?
The first chart of the IZCT involving the issue to be resolved is administered as a Silent
Answer Test, with the examinee instructed to “listen to the questions, make sure you
understand the questions, and most importantly at the end of this test you will have your
last chance to make changes before your answers are recorded; if you remember anything
you have not told me about, as soon as the test is over please tell me.” The chart sequence
is: 1, 2, 3, 4, C5, R6, C8, R9, C11, R12, 13 (irrelevant questions 7 and 10 are not used unless
they are needed to reestablish a norm due to an artifact).
The second chart is administered with the relevant questions rotated in a clockwise man-
ner, and question 3 is used near the end of the chart, reworded, “Did you deliberately lie to
any test question?”: 1, 2, C5, R12, C8, R6, C11, R9, 3, 13. Irrelevant questions 4, 7, and 10 are
not used unless it is necessary to reestablish a norm after an artifact.
The third chart is administered by again rotating the relevant questions clockwise; how-
ever, the relevant questions are now asked before the comparison questions: 1, 2, 3, R9, C5,
R12, C8, R6, C11, 13. By now the truthful examinee is very focused on the threat created by
the comparison questions and can do well in this relevant-comparison sequence. The test
21. THE INSTRUMENTAL DETECTION OF DECEPTION: POLYGRAPH
309
FIGURE 21.4 Polygraph chart showing strong reactions to relevant questions.
for the deceptive examinee generally creates very clear data. At the end of three charts, each of
the relevant questions would have appeared next to each of the comparison questions once.
A fourth chart containing all test questions in order (1 to 13) is administered if the data
does not seem to support a definite decision as to truth or deception, or if deliberate distor-
tions are suspected. Most examinees using deliberate distortions fall into a naive category
and will attempt to distort their truthful answers to irrelevant questions, in the hopes that
their reactions to deceptive answers will then not look so bad. Therefore, in Chart 4, all four
irrelevant questions are asked to allow for this deliberate attempt to defeat the test.
In a 2001 study performed for the Department of Defense Polygraph Institute, a limited
review of literature published between January 1986 and May 2001 was conducted to eval-
uate studies reporting the accuracy and reliability of screening and diagnostic tests in poly-
graph, medicine, and psychology [3]. Data for 198 studies were collected from 145 articles.
Accuracy estimates are the combined average of sensitivity and specificity across all studies
found within a particular category (1.00 ¼ 100% accuracy).
The reviewers found that for field diagnostic assessments, the accuracy of polygraph was
.88, medical was .86, and psychological tools was .70. For field screening assessments, the
accuracy of polygraph was .74, medical was .86, and psychological tools was .76.
The average accuracy reported for 37 diagnostic polygraph studies (specific issue) was
similar to magnetic resonance imaging (17 studies), computed tomography (19 studies),
310
21. THE INSTRUMENTAL DETECTION OF DECEPTION: POLYGRAPH
FIGURE 21.5 (A) Lafayette LX 4000 Computerized Polygraph System. (B) Stoelting Ultra Scribe Analog
Polygraph Instrument.
and ultrasound (38 studies). The Minnesota Multiphasic Personality Inventory (MMPI) had
the lowest reported accuracy (17 studies).
The study concluded that the level of accuracy and agreement reported in the polygraph
literature is consistent with the medical and psychological literature.
There are four major manufacturers of polygraph instruments in North America (Figure 21.5).
Lafayette Instrument Company (www.lafayetteinstrument.com), Stoelting Instrument Company (www.stoeltingco.com), and Axciton Instrument Company (www.axciton.com) are located in the United States, and Limestone Technologies (www.limestonetech.com) is located in Canada. All four provide computerized systems; only Lafayette and Stoelting still provide analog instruments. The major advantage of computerized systems is that they allow for
quality control of the data collected via computerized algorithms.
There are numerous professional associations for polygraph examiners in the United
States and around the world. The largest and most prestigious is the American Polygraph
Association (www.polygraph.org), followed by the American Association of Police Polygraphists (www.policepolygraph.org).
The future of truth verification does not appear to make the polygraph extinct. Instead,
the future looks like a search for what additional data can be ascertained and added to
the polygraph to make it even more accurate, especially for truthful suspects.
SUMMARY
• The polygraph testing procedure remains the “gold standard” for truth verification.
• There are various types of tests and various types of technique formats.
• The most accurate procedure utilizes a “single-issue” examination and a Zone
Comparison Technique format.
SUMMARY
311
• The most prestigious and largest association of polygraph examiners is the American
Polygraph Association.
References
[1] J.A. Matte, Forensic Psychophysiology; Using the Polygraph, JAM Publications, Williamsville, NY, 1996.
[2] D. Krapohl, J. McCloughan, S. Senter, How to use the concealed information test, Polygraph 35 (3) (2006) 123 138.
[3] P.E. Crewson, A Comparative Analysis of Polygraph with Other Screening and Diagnostic Tools, Department
of Defense Polygraph Institute, Contract No. DABT60 01 P 3017, 2001.
C H A P T E R
22
The Search for Truth: Future
Instrumentation
From the beginning of time, there has been a need to determine truth. In our earliest
writings we see these attempts. When Adam was questioned in the Bible, he attempted to
rationalize his bite of the apple by blaming Eve, who in turn blamed the snake. When Abel
was asked where his brother was, he answered with the question, “Am I my brother’s
keeper?” and showed the sensitivity of the question, as well as his culpability, by not
answering.
Since the 1800s, humankind has searched for instrumentation to aid them in their
attempts at truth verification. In this chapter we look at the instrumentation of today and
the future, as well as attempt to give you some sense of the scientific validity of each
instrument.
The polygraph is without question the gold standard of truth verification today. The
American Polygraph Association has a compendium of research studies available on the
validity and reliability of polygraph testing [1]. The 80 research projects listed, published since 1980, involved 6380 polygraph examinations or sets of charts from examinations.
Researchers conducted 12 studies of the validity of field examinations, following 2174 field
examinations, providing an average accuracy of 98%. Researchers conducted 11 studies
involving the reliability of independent analyses of 1609 sets of charts from field examina-
tions confirmed by independent evidence, providing an average accuracy of 92%. Research-
ers conducted 41 studies involving the accuracy of 1787 laboratory simulations of
polygraph examinations, producing an average accuracy of 80%. Researchers conducted
16 studies involving the reliability of independent analyses of 810 sets of charts from labo-
ratory simulations, producing an average accuracy of 81%.
Although overall
accuracy of polygraph is very high, when errors do occur they tend to
be false positives: truthful suspects determined to be deceptive. As mentioned earlier, this
bias is exactly opposite that of the forensic interview, which tends to err in favor of decep-
tive suspects, resulting in false negatives.
Today most polygraph examiners are utilizing computerized polygraph systems.
The minimum physiological data collected is thoracic and abdominal breathing, electro-
dermal activity, and cardiovascular changes, such as blood volume/pressure and pulse rate.
Effective Interviewing and Interrogation Techniques
313
# 2011, Elsevier Ltd.
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22. THE SEARCH FOR TRUTH: FUTURE INSTRUMENTATION
The major advantage of these computerized systems is that they allow for scoring algorithms
to be utilized for quality control of the examiner’s interpretation of the data collected. (See
Figures 22.1 and 22.2.)
Because of concern over countermeasures, in 2012 the American Polygraph Association
will require instruments to also utilize a countermeasure device that will help the examiner
identify artifacts and attempts at physical countermeasures.
Voice Stress was first introduced in the 1970s by a Virginia company, Dektor
Counterintelligence. The company executives (Bell, McQuiston, and Ford) were retired mil-
itary personnel who had been stopped from doing research into the covert possibilities of
lie detection. Before their retirement they had looked at the feasibility of three methods
for accomplishing their goal: laser beams that could monitor physiology without a person’s
knowledge from a distance, changes in odor caused by fear, and changes in the
voice. On retirement, they began manufacturing the Psychological Stress Evaluator (PSE),
which they claimed could detect deception by changes in microtremors in the voice when
a person lied.
FIGURE 22.1 The Academy for Scientific Investigative Training’s “ASIT POLYSUITE” Scoring Algorithm.
22. THE SEARCH FOR TRUTH: FUTURE INSTRUMENTATION
315
FIGURE 22.2 Lafayette Instrument Company
LX 4000 Computerized Polygraph System.
Since the introduction of the PSE, many other instruments have been offered, including a
computerized voice stress analyzer first developed by McQuiston in Florida, as well as sys-
tems being offered out of Israel.
Since 9/11, we have been sure that the U.S. government would find a device that
Nathan J Gordon, William L Fleisher Page 46