their own lip as they violently shake their head from side to side like an animal tearing
at meat.
What can we do as interviewers or investigators to deal with aggressive people? The
Crisis Prevention Institute, Inc., of Brookfield, Wisconsin, suggests “Seven Principles for
Effective Verbal Intervention”:
1. Remain Calm. Remember, the verbally escalating person is beginning to lose control.
If the person also perceives that you are losing control, the situation will get worse. Try
to keep your cool, even when challenged, insulted or threatened.
2. Remove the Audience. Onlookers, especially those who are peers of the verbally
escalating person, tend to fuel the fire. They often become cheerleaders, encouraging the
individual. Isolate the person that is losing control, and you will be much more effective
one-on-one.
3. Keep It Simple. Be clear and direct in your message. Avoid jargon and complex
opinions.
4. Watch Your Body Language. Be aware of your space, posture and gestures. Make sure
your nonverbal behavior is consistent with your verbal message. We would also suggest
that you use your hands to illustrate, keeping your palms open and hands up. While this
conveys a nonverbal message of truthfulness and nonaggression, it deceptively allows
you to place your hands almost in a fighting position, allowing you to defend or attack
quickly if need be.
5. Use Silence. Ironically, silence is one of the most effective verbal techniques available.
Silence on your part allows the individual to clarify and restate his or her position. This
often leads to a clearer understanding of the true source of the individual’s conflict.
6. Use Reflective Questioning. Paraphrase and restate comments. By repeating or reflecting
the person’s statement in the form of a question, you’ll help the individual gain valuable
insight, as well as let the person know you are paying attention to what they are saying.
7. Watch Your Paralinguistics. Any two identical statements can have completely opposite
meanings, depending on how the tone, volume and cadence of your voice are altered.
Make sure the words you are using are consistent with your voice inflection to avoid
double meanings.
So, why do people get angry? Here are some reasons:
1. Misunderstanding
2. Feel they are not being heard
3. Being fatigued or hungry
4. Feeling like they are getting a runaround
5. Baggage (bad prior experience)
6. Having suffered a loss
7. Bad hair day
8. Feeling they are not being treated fairly
9. Lack of feeling empowered
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20. UNDERSTANDING AGGRESSIVE BEHAVIOR AND DEALING WITH ANGRY PEOPLE
What are the steps and warning signs that lead up to physical violence?
1. Suspect becomes anxious.
2. Suspect starts acting nervous, or demonstrating a lot of displacement activity. (When you
see these early signs that may lead up to violence, you need to be supportive and
continue to offer help to the person.)
3. Face blanches or pales.
4. Speech becomes incoherent.
5. Suspect becomes defensive.
6. Suspect begins to act irrational or belligerent, or challenges you. (When you receive these
signs, you must now give the suspect clear choices and offer advantages and consequences
for their behavior.)
Years ago, one of the authors attended a seminar for dealing with angry people where
they used the acronym “SOFTEN” as a protocol for deescalating someone’s anger. We offer
it to the reader as an excellent tool in these potentially dangerous situations:
• Smile with discretion – nonverbally let the suspect know you care about them and that
you are not becoming angry.
• Open body positioning – demonstrates that you are being truthful with the suspect and
open with them.
• Forward body lean – shows you are interested in what they are saying.
• Territory – do not forget the rules of proxemics. †
• Eye Contact – proper eye contact is a sign of truthfulness.
• Nod Attentively – to show the suspect you are paying attention.
To further demonstrate that you are interested and paying attention to the suspect, ask
questions and restate his concerns. Speak softly; do not try to meet power with power.
Use phrases that begin with, “I want to help you,” preceded or followed by the suspect’s
name. Continue to use alternatives and hooks.
PREATTACK WARNING SIGNS
• Tense body
• Eyebrows pulled down and in (anger)
• Eyebrows lowered and pulled together (aggression)
• Tense eyelids
• Narrowing of eye opening
• Dilating pupils
• San pak ku
• Suddenly and markedly blanched face‡
• Protruding tongue/pursed lips
• Jutted jaw
• Tucked chin
†Proxemics is the understanding and use of interpersonal body distances.
‡In very dark skinned people, this may manifest itself as a sudden “graying” or pallid look. Please note that
“red faced” individuals are less likely to attack, because they are actually in a parasympathetic, or relief, mode, whereas the blanched faced individual is in the sympathetic, or fight/flight, mode.
SUMMARY
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• Thinning lips
• Baring of teeth, or snarling
• Fighting stance
• Sudden shift of weight
• Intention movement gestures
• Vacuum gestures
• Redirection gestures
• Raised tones
• Quicker speech tempo
• Invasion of space
SUMMARY
• Aggression is often born out of frustration.
• There are times when a guilty suspect will fake aggression in an attempt to create an
argument and escape the interview room.
• Interviewers should be able to recognize genuine aggressive intent on the part of the
subject through understanding its psychophysiological and social roots.
• The reader will be able to identify key nonverbal indicators of aggression. Humans tend
to seek to be around persons who are “like” themselves and denigrate as scapegoats
those who are perceived to be “different.”
• Interviewers can develop skills to diffuse aggression and prevent it from accelerating
into assaultive behavior.
C H A P T E R
21
The Instrumental Detection
of Deception: Polygraph
The word polygraph is derived from Latin: poly meaning “many,” and graph meaning
“writings.” Literally, then, polygraph means “many writings,” indicating that the polygraph
monitors more than one physiological system. The evolution of the polygraph, as we know
it today, began in 1921, when August Vollmer,* Chief of Police of the Berkeley, California, Police Department, assigned one of his officers, John Larson (Figure 21.1), to investigate the feasibility of developing a “lie detector” to be used as an investigative tool. Larson’s first
instrument simultaneously recorded respiration and cardiovascular activity.
One of the people trained by Larson in this new art was Leonarde Keeler, who became
known as the “Father of the Modern Polygrap
h” (Figure 21.2). Keeler developed many
improvements in both the instrumentation and the polygraph technique, to include the
monitoring of a third physiological parameter of electrodermal activity: sweating of the
fingertips.
The Berkeley, California, Police Department became the first law enforcement agency in
the world to have this new investigative tool. However, the first use of an instrument in the
detection of deception occurred many years before, in Italy, in 1895. Cesare Lombrosso,
considered to be the “Father of Modern Criminology,” conducted a test for an Italian law
enforcement agency, during the investigation of the murder of a child. He placed the sus-
pect’s hand into a device that monitored changes in blood volume as he showed the suspect
pictures of children, one of which was the dead child. He theorized that if the suspect was
innocent, there would be no unusual changes in the suspect’s blood volume as he viewed
the pictures, because all of the pictures were of children he did not know. However, if
the suspect was the murderer, seeing the child he murdered would cause a psychophysio-
logical change, resulting in a discernible increase in blood volume.
*August Vollmer is regarded by many as the foremost figure in modernizing American police agencies. He
instituted many innovations in addition to the polygraph, such as radio communications and crime labs.
Chief Vollmer was also the first president of the International Association of Chiefs of Police (IACP). In fact, each year the IACP presents the August Vollmer Award to an individual who has achieved a remarkable
scientific innovation in police work.
Effective Interviewing and Interrogation Techniques
297
# 2011, Elsevier Ltd.
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21. THE INSTRUMENTAL DETECTION OF DECEPTION: POLYGRAPH
FIGURE 21.1 Larson at the Berkeley,
California, Police Department.
FIGURE 21.2 Leonarde Keeler “Father of the Modern Polygraph.”
Today, polygraph techniques or formats can be divided into two categories: “recognition
tests,” and “truth verification” or “lie tests.” The test format used by Lombrosso would be
categorized as a “recognition test” in the form of a “known solution peak of tension test.”
This type of format consists of a “preparatory question,” a “pre-fix question,” a “key ques-
tion,” and several “buffer or padding questions.”
Imagine in the case described earlier if Lombrosso had numbered the pictures of the chil-
dren, and during the presentations he asked the following questions:
21. THE INSTRUMENTAL DETECTION OF DECEPTION: POLYGRAPH
299
Preparatory:
Regarding that dead child,
Pre-fix:
Do you know if it was the child in:
Padding
Picture 1?
Padding
Picture 2?
Key
Picture 3? (Correct Answer)
Padding
Picture 4?
Padding
Picture 5?
Padding
Picture 6?
By definition, a “known solution peak of tension test” is when a series of questions, usually
five to nine, are asked in which there are several buffer or padding questions (incorrect items)
and one key item (correct answer). Only the examiner and the actual perpetrator would know
which was the correct answer. Questions in this format are reviewed with the suspect in order,
so that if the suspect is the perpetrator, he himself knows when the “key,” or correct item, will be
asked. The closer the key question gets, the greater the guilty person’s physiological tension,
until the lie is told, and then that tension decreases in relief. Hence the name “peak of tension.”
Usually, an examiner using this format will administer the questions two to three times before
attempting to make a determination. There are several variations of this technique, including a
“false key peak of tension, “guilty knowledge test,” and “concealed information test.”
The “false key peak of tension” is credited to Richard O. Arther [1], an early pioneer in the field of polygraph testing. In this test the examiner would ask a question early in the
pretest interview that would lead an innocent suspect to incorrectly deduce this inquiry
item is germane to the crime and is the actual “key” for the guilty party. Thus, the innocent
suspect’s psychological focus would be oriented onto the “false key,” which would result in
greater psychophysiological reactions for the innocent person to this question than to the
actual “key,” thus allowing the examiner to make a determination that the suspect was in
fact innocent because his psychological set was on the false item.
For example, assume that there was a burglary at an office and a DVD player was stolen.
During the interview before the polygraph examination, the examiner may ask the suspect
if he ever took a typing course. The question formulation for the “False Key” Peak of Ten-
sion test might be as follows:
Preparatory:
Regarding that item taken from that office broken into last night,
Pre-fix:
do you know if it was a
Padding
Monitor?
False Key
Typewriter?
Padding
Copier?
Key
DVD player? (Correct Answer)
Padding
Computer?
Padding
Safe?
Padding
Shredder?
Because the examiner had questioned the innocent suspect about his use of typewriters early
in the pretest interview, and he did not know the actual item stolen (key), his focus and greatest
psychophysiological changes would most likely occur with the typewriter (false key). If the
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21. THE INSTRUMENTAL DETECTION OF DECEPTION: POLYGRAPH
suspect was the perpetrator, he would recognize the item he stole was the DVD player, and his
focus and greatest psychophysiological reaction would be to the “key” question.
A variation of the “known solution peak of tension test” is the “guilty knowledge test”
[2]. In this test the suspect is not made aware of the question order and never knows when the “key” question will be asked. The examiner, in fact, moves the position of the “key”
question in each of the charts administered and observes the consistency of reactions to
the “key” question to make a determination. For example, in the case just cited, the follow-
ing questions would be reviewed out of order, and the examiner would change the question
order in each chart administered:
Preparatory:
Regarding that item taken from that office broken into last night,
Pre-fix:
do you know if it was a
CHART 1
CHART 2
Padding
Monitor?
Padding
Shredder?
Padding
Copier?
Padding
Monitor?
Key
DVD player? (Correct Answer)
Padding
Computer?
Padding
Computer?
Key:
DVD player? (Correct Answer)
Padding
Safe?
Padding:
Copier?
Padding
Shr
edder?
Padding:
Safe?
A more recent derivative of this test is the “concealed information test” [3]. Again, this is a “known solution peak of tension test” where the examiner runs several charts; however,
now each individual chart will deal with a different set of questions concerning a different
aspect of the same crime. As in the “guilty knowledge test,” the suspect does not know the
question order, and the position of the “key” question changes in each of the charts
administered.
CHART 1:
Preparatory:
Regarding that office broken into last night,
Prefix:
do you know if it was on
Padding:
Chestnut Street?
Padding:
Lombard Street?
Padding:
Market Street?
Key:
Locust Street?
Padding:?
Pine Street?
Padding:
Spruce Street?
Padding:
Walnut Street?
Padding:
Arch Street?
CHART 2:
Preparatory:
Regarding that office broken into last night,
Prefix:
do you know if the office was on the
Padding:
1st floor?
Padding:
5th floor?
Key:
2nd floor?
Padding:
8th floor?
21. THE INSTRUMENTAL DETECTION OF DECEPTION: POLYGRAPH
301
Padding:
3rd floor?
Padding:
6th floor?
Padding:
4th floor?
CHART 3:
Preparatory:
Regarding that item taken from that office
broken into last night,
Pre-fix:
Do you know if it was a
Padding
Monitor?
Padding
Copier?
Key
DVD player?
Padding
Computer?
Padding
Safe?
Padding
Shredder?
The “searching peak of tension test” is where the examiner does not actually know the
correct answer; only the guilty suspect does. As in the original peak of tension test, suspects
are aware of question order, and the questions are the examiner’s most likely solutions to
the crime. One of the most unusual applications of this test the authors are aware of
occurred in Israel. Israeli intelligence had information that a suspect had planted a bomb
Nathan J Gordon, William L Fleisher Page 44