PolygraphyPolygraphy

The Science of LieThe Science of Lie DetectionDetection

Operational TermsOperational Terms

POLYGRAPHPOLYGRAPH – is an instrument for the – is an instrument for the recording of changes in blood pressure; pulse recording of changes in blood pressure; pulse rate, respiration and skin resistance as rate, respiration and skin resistance as indication of emotional disturbances especially indication of emotional disturbances especially of lying when questioned.of lying when questioned.

The word was derived from the word The word was derived from the word POLYPOLY means “means “manymany” and ” and GRAPHSGRAPHS means “ means “writing writing chart”chart”..

POLYGRAPHYPOLYGRAPHY – it is the scientific method – it is the scientific method of detecting deception, using a polygraph of detecting deception, using a polygraph machine.machine.

FEAR FEAR – is emotional response to specific – is emotional response to specific danger that appears to beyond a persons danger that appears to beyond a persons defensive power.defensive power.

STIMULUSSTIMULUS – is a force or motion reaching – is a force or motion reaching the organism and excites the receptors.the organism and excites the receptors.

REACTIONREACTION – it is an action in mental attitude – it is an action in mental attitude evokes by external influence.evokes by external influence.

DECEPTION DECEPTION – is an act of deceiving or – is an act of deceiving or misleading usually accompanied by lying.misleading usually accompanied by lying.

DETECTIONDETECTION – It is an act of discovery of – It is an act of discovery of existence, presence of fact or something existence, presence of fact or something hidden or obscure.hidden or obscure.

LYING LYING – the uttering or conveying of – the uttering or conveying of falsehood or creating a false or misleading falsehood or creating a false or misleading information with the intention of affecting information with the intention of affecting wrongfully the acts and opinion of other.wrongfully the acts and opinion of other.

RESPONSERESPONSE – is any activity or inhibition of – is any activity or inhibition of the previous activity of an organism resulting the previous activity of an organism resulting from stimulation.from stimulation.

SPECIFIC RESPONSESPECIFIC RESPONSE – is any deviation – is any deviation from the normal tracing of the subject.from the normal tracing of the subject.

NORMAL TRACINGNORMAL TRACING – is a tracing on the – is a tracing on the chart wherein the subject answered in the chart wherein the subject answered in the irrelevant question.irrelevant question.

POLYGRAPH EXAMINERPOLYGRAPH EXAMINER – is one who – is one who conducts and administer the test.conducts and administer the test.

CHART OR POLYGRAMSCHART OR POLYGRAMS – refers to the – refers to the composite records of pneumograph, composite records of pneumograph, Galvanograph and cardiosphygmograph Galvanograph and cardiosphygmograph tracings recorded from series of questions.tracings recorded from series of questions.

Subject Subject – refers to the person being examined.– refers to the person being examined.

Early Methods of detecting Early Methods of detecting deceptiondeception

Trial by CombatTrial by Combat Trial by OrdealTrial by Ordeal Trial by Iron Hot OrdealTrial by Iron Hot Ordeal Ordeal by BalanceOrdeal by Balance Ordeal of Rice ChewingOrdeal of Rice Chewing Donkey’s Tall OrdealDonkey’s Tall Ordeal

PolygraphPolygraph

The polygraph is used to test or question The polygraph is used to test or question individuals for the purpose of detecting individuals for the purpose of detecting deception or verifying truth of statements deception or verifying truth of statements through a visual, permanent and through a visual, permanent and simultaneous recording of a person’s simultaneous recording of a person’s cardiovascular and respiratory pattern as cardiovascular and respiratory pattern as a minimum instrumentation requirement.a minimum instrumentation requirement.

A A polygraphpolygraph (commonly referred to as a (commonly referred to as a lie detector) ) is an instrument that measures and records several is an instrument that measures and records several physiological responses such as:physiological responses such as: blood pressure,, pulse, , respiration and and skin conductivity

while the subject is asked and answers a series of while the subject is asked and answers a series of questions, on the basis that false answers will produce questions, on the basis that false answers will produce distinctive measurements. The polygraph measures distinctive measurements. The polygraph measures physiological changes caused by the physiological changes caused by the sympathetic nervous system during questioning. during questioning.

Within the U.S. federal government, Within the U.S. federal government, a polygraph examination is also a polygraph examination is also

referred to as a referred to as a PSYCHOPHYSIOLOGICAL PSYCHOPHYSIOLOGICAL

DETECTION OF DECEPTIONDETECTION OF DECEPTION (PDD) examination. Several other (PDD) examination. Several other technologies are also used in the technologies are also used in the

field of field of lie detection, but the , but the polygraph is the most famous.polygraph is the most famous.

HistoryHistory

The idea that lying produces physical side-effects has The idea that lying produces physical side-effects has long been claimed. In long been claimed. In West Africa persons suspected persons suspected of a crime were made to pass a of a crime were made to pass a bird's egg to one 's egg to one another. If a person broke the egg, then he or she was another. If a person broke the egg, then he or she was considered guilty, based on the idea that their considered guilty, based on the idea that their nervousness was to blame. In nervousness was to blame. In ancient China the the suspect held a handful of suspect held a handful of rice in his or her in his or her mouth during a prosecutor's speech. Since during a prosecutor's speech. Since salivation was was believed to cease at times of emotional believed to cease at times of emotional anxiety, the , the person was considered guilty if by the end of that person was considered guilty if by the end of that speech the rice was dry.speech the rice was dry.

18951895

Cesare LombrosoCesare Lombroso, an Italian scientist, , an Italian scientist, employed the first scientific instrument to employed the first scientific instrument to detect deception – detect deception – HYDROSPHYMOGRAPHHYDROSPHYMOGRAPH, measured , measured changes in pulse and blood pressure when changes in pulse and blood pressure when suspects were questioned about their suspects were questioned about their involvement of a specific offense.involvement of a specific offense.

19141914

VITTORIO BENUSSI successfully VITTORIO BENUSSI successfully detected deception with a detected deception with a PNEUMOGRAPH – an instrument that PNEUMOGRAPH – an instrument that graphically measures an examinee’s graphically measures an examinee’s inhalation and exhalation. Benussi thus inhalation and exhalation. Benussi thus demonstrated that changes in breathing demonstrated that changes in breathing patterns accompany deceptionpatterns accompany deception..

19171917

Further research by Further research by WILLIAM WILLIAM MARSTONMARSTON in 1917 dealt with the in 1917 dealt with the SPHYGMOMANOMETER, SPHYGMOMANOMETER, which was used to obtain periodic which was used to obtain periodic discontinuous blood pressure discontinuous blood pressure readings during the course of an readings during the course of an examination.examination.

19201920

A device recording both blood-pressure and A device recording both blood-pressure and

galvanic skin response was invented in was invented in

1920 by 1920 by Dr. Dr. John A. Larson of the of the University of California and first applied in and first applied in law enforcement work by the law enforcement work by the Berkeley Police Police Department under its nationally renowned Department under its nationally renowned police chief police chief August Vollmer

. . Further work on this device was Further work on this device was done by Leonarde Keeler.[2] The done by Leonarde Keeler.[2] The first time the term "polygraph" first time the term "polygraph" was used was in 1906 by James was used was in 1906 by James MacKenzie in his invention the MacKenzie in his invention the "ink polygraph," which was used "ink polygraph," which was used for medical reasons.for medical reasons.

Makenzie wrote a second paper on the concept in 1915, when Makenzie wrote a second paper on the concept in 1915, when finishing his undergraduate studies. He entered Harvard Law finishing his undergraduate studies. He entered Harvard Law School and graduated in 1918, re-publishing his earlier work School and graduated in 1918, re-publishing his earlier work in 1917.[3] According to their son, Marston's wife, Elizabeth in 1917.[3] According to their son, Marston's wife, Elizabeth Holloway Marston, was also involved in the development of Holloway Marston, was also involved in the development of the systolic blood-pressure test: "According to Marston’s son, the systolic blood-pressure test: "According to Marston’s son, it was his mother Elizabeth, Marston’s wife, who suggested to it was his mother Elizabeth, Marston’s wife, who suggested to him that 'When she got mad or excited, her blood pressure him that 'When she got mad or excited, her blood pressure seemed to climb' (Lamb, 2001). Although Elizabeth is not seemed to climb' (Lamb, 2001). Although Elizabeth is not listed as Marston’s collaborator in his early work, Lamb, listed as Marston’s collaborator in his early work, Lamb, Matte (1996), and others refer directly and indirectly to Matte (1996), and others refer directly and indirectly to Elizabeth’s work on her husband’s deception research. She Elizabeth’s work on her husband’s deception research. She also appears in a picture taken in his polygraph laboratory in also appears in a picture taken in his polygraph laboratory in the 1920s (reproduced in Marston, 1938)."[4][5] The comic the 1920s (reproduced in Marston, 1938)."[4][5] The comic book character, Wonder Woman by William Marston (and book character, Wonder Woman by William Marston (and influenced by Elizabeth Marston[6][7] ) carries a magic lasso influenced by Elizabeth Marston[6][7] ) carries a magic lasso which was modelled upon the systolic blood-pressure test.[8]which was modelled upon the systolic blood-pressure test.[8][6][6]

Marston was the self proclaimed “Marston was the self proclaimed “father of the father of the polygraph”polygraph” despite his predecessor's despite his predecessor's contributions. Marston remained the device's contributions. Marston remained the device's primary advocate, lobbying for its use in the primary advocate, lobbying for its use in the courts. In 1938 he published a book, courts. In 1938 he published a book, The Lie The Lie Detector Test,Detector Test, wherein he documented the wherein he documented the theory and use of the device.[9] In 1938 he theory and use of the device.[9] In 1938 he appeared in advertising by the Gillette appeared in advertising by the Gillette company claiming that the polygraph showed company claiming that the polygraph showed Gillette razors were better than the Gillette razors were better than the competition.[10][11][12]competition.[10][11][12]

CARDIOSPHYGMOGRAPHCARDIOSPHYGMOGRAPH

CESARE LOMBROSOCESARE LOMBROSO – accorded as – accorded as the first person that utilizes instrument the first person that utilizes instrument in detecting deception.in detecting deception. His basis in detecting deception is by His basis in detecting deception is by

measuring the blood pressure and pulse measuring the blood pressure and pulse rate.rate.

This is known as This is known as HYDROSPHYGMOGRAPHHYDROSPHYGMOGRAPH

ANGELO MOSSOANGELO MOSSO – he stated that – he stated that FEAR influenced the heart and could FEAR influenced the heart and could be use as a basis for detecting be use as a basis for detecting deception. He uses sphygmanometer deception. He uses sphygmanometer and scientific radio to study fearand scientific radio to study fear

DR. WILLIAM MARSTONDR. WILLIAM MARSTON – – he conducted numerous tests for detecting he conducted numerous tests for detecting deception and utilizes the change in deception and utilizes the change in systolic pressure to determine deception.systolic pressure to determine deception.

He also developed his own method of He also developed his own method of reading systolic blood pressure. reading systolic blood pressure.

Self proclaim father of polygraphSelf proclaim father of polygraph

JOHN A. LARSONJOHN A. LARSON – the real – the real “Father of lie detection”. “Father of lie detection”.

The present polygraph machine is The present polygraph machine is attributed to him. He is the en who attributed to him. He is the en who develop and study to record at the same develop and study to record at the same time the responses of the blood pressure, time the responses of the blood pressure, pulse rate and respirationpulse rate and respiration

GALVANOGRAPH COMPONENTGALVANOGRAPH COMPONENT

STICKERSTICKER – he introduced the method of – he introduced the method of detecting deception from the galvanic detecting deception from the galvanic impression on the chart tracing.impression on the chart tracing.

VERGUTHVERGUTH – he used the word – he used the word PSYCHOGALVANIC reflexPSYCHOGALVANIC reflex. He believed that . He believed that electrical phenomena are due to the activity of electrical phenomena are due to the activity of sweat glands, and such activity is known as sweat glands, and such activity is known as “psychogalvanic”.“psychogalvanic”.

PNEUMOGRAPH COMPONENTPNEUMOGRAPH COMPONENT

VITTORIO BENUSSIVITTORIO BENUSSI – he noted changes in – he noted changes in inhalation ratio during indications of inhalation ratio during indications of deceptions.deceptions.

LEONARD KEELERLEONARD KEELER

he device a metal recording bellows; rolled he device a metal recording bellows; rolled chart paper.chart paper.

In 1949, he incorporated Galvanograph with In 1949, he incorporated Galvanograph with measurement of blood pressure and respiration measurement of blood pressure and respiration into a portable case.into a portable case.

The four Major components The four Major components

PNEUMOGRAPHPNEUMOGRAPH CARDIOSPHYGMOGRAPH CARDIOSPHYGMOGRAPH

COMPONENTCOMPONENT GALVANOGRAPH COMPONENTGALVANOGRAPH COMPONENT KEYMOGRAPH COMPONENTKEYMOGRAPH COMPONENT

Today, polygraph examiners use two Today, polygraph examiners use two types of instrumentation: types of instrumentation:

analog analog computerizedcomputerized

In the United States, most examiners now In the United States, most examiners now use computerized instrumentation.use computerized instrumentation.

An analog polygraph instrumentMost analog polygraphs are being replaced by digital

devices.

Today, most polygraph exams are administered with digital equipment like this.

The polygraph instrument has undergone a The polygraph instrument has undergone a dramatic change in the last decade. For many dramatic change in the last decade. For many years, polygraphs were those instruments that years, polygraphs were those instruments that you see in the movies with little needles you see in the movies with little needles scribbling lines on a single strip of scrolling scribbling lines on a single strip of scrolling paper. These are called paper. These are called analog polygraphsanalog polygraphs. . Today, most polygraph tests are administered Today, most polygraph tests are administered with digital equipment. The scrolling paper with digital equipment. The scrolling paper has been replaced with sophisticated has been replaced with sophisticated algorithms and algorithms and computer monitorscomputer monitors. .

Modern scientific methods have been devised Modern scientific methods have been devised utilizing knowledge of physiology, utilizing knowledge of physiology, psychology, pharmacology, toxicology, etc. in psychology, pharmacology, toxicology, etc. in determining whether a subject is telling the determining whether a subject is telling the truth or not. Although a scientific method of truth or not. Although a scientific method of deception detection have not yet attain legal deception detection have not yet attain legal recognition to have their results admissible as recognition to have their results admissible as an evidence in court, they have been an evidence in court, they have been considered very useful as aids in criminal considered very useful as aids in criminal investigation.investigation.

Methods of deception detectionMethods of deception detection

1.1. Devices which record the psycho-Devices which record the psycho-physiological response.physiological response.

2.2. Use of drugs that try to inhibit the inhibitorUse of drugs that try to inhibit the inhibitor

3.3. HypnotismHypnotism

4.4. By observationBy observation

5.5. Scientific InterrogationScientific Interrogation

6.6. ConfessionConfession

Recording the Psycho physiological Recording the Psycho physiological Response:Response: The nervous control of the human body The nervous control of the human body

includes the central nervous system (the includes the central nervous system (the brain and the spinal cord) and the autonomic brain and the spinal cord) and the autonomic or regulating nervous system (sympathetic or regulating nervous system (sympathetic and parasympathetic). The central nervous and parasympathetic). The central nervous system primarily controls the motor and system primarily controls the motor and sensory functions that occur at or above the sensory functions that occur at or above the threshold. It maybe voluntary.threshold. It maybe voluntary.

The autonomic nervous system acts as a The autonomic nervous system acts as a self-regulating autonomic response of the self-regulating autonomic response of the body.body.

The autonomic nervous system is The autonomic nervous system is composed of two complimentary branches: composed of two complimentary branches: thethe sympatheticsympathetic and the and the parasympatheticparasympathetic nervous system, acting opposite each nervous system, acting opposite each other.other.

The fibers of both enervate all organs The fibers of both enervate all organs where self-regulation is essentialwhere self-regulation is essential

When a person is under the influence of When a person is under the influence of physical (exertion) or emotional (anger, physical (exertion) or emotional (anger, excitement, fear, lie detection, etc.) excitement, fear, lie detection, etc.) stimuli, the sympathetic will dominate stimuli, the sympathetic will dominate and over-ride the parasympathetic, thus and over-ride the parasympathetic, thus there will be a changes in the heart rate, there will be a changes in the heart rate, pulse rate, blood pressure, respiratory pulse rate, blood pressure, respiratory tracing, psycho galvanic reflexes, time of tracing, psycho galvanic reflexes, time of response to question, voice tracing, etc.response to question, voice tracing, etc.

The parasympathetic nervous system works to The parasympathetic nervous system works to restore things to normal when the conditions restore things to normal when the conditions of stress have been removed. It is the dominant of stress have been removed. It is the dominant branch when the condition is normal and the branch when the condition is normal and the subject is calm, contented and relaxed.subject is calm, contented and relaxed.

The recording of some of the psycho-The recording of some of the psycho-physiological reaction of a subject when he is physiological reaction of a subject when he is subjected to a series of questions, and the subjected to a series of questions, and the scientific interpretation by trained experts are scientific interpretation by trained experts are the basis of the tests. the basis of the tests.

Word Association TestWord Association Test

A list of stimulus and non-stimulus words are A list of stimulus and non-stimulus words are read to the subject who is instructed to answer read to the subject who is instructed to answer as quickly as possible. as quickly as possible.

The answer to the questions may be a “yes” or The answer to the questions may be a “yes” or a “no”.a “no”.

Unlike the lie detector , the time interval Unlike the lie detector , the time interval between the words uttered by the examiner between the words uttered by the examiner and the answer of the subject is recorded.and the answer of the subject is recorded.

When the subject is asked questions with When the subject is asked questions with reference to his name, address, civil status, reference to his name, address, civil status, nationality, ect. Which has no relation to the nationality, ect. Which has no relation to the subject-matter of the investigation, the subject-matter of the investigation, the tendency is to answer quickly.tendency is to answer quickly.

But when the questions bear some words But when the questions bear some words which have to do with the criminal acts the which have to do with the criminal acts the subject allegedly committed, like knife, gun, subject allegedly committed, like knife, gun, or hammer which was used in the killing, the or hammer which was used in the killing, the tendency is to delay the answer.tendency is to delay the answer.

The test is not concerned with the The test is not concerned with the answer, be it a ‘yes” or a “no”. The answer, be it a ‘yes” or a “no”. The important factor is the time of important factor is the time of response in relation to stimulus or response in relation to stimulus or non-stimulus words.non-stimulus words.

Like the use of the lie detector, the Like the use of the lie detector, the subject cannot be compelled to be subject cannot be compelled to be subjected to the test without his subjected to the test without his consent.consent.

Psychological Stress EvaluatorPsychological Stress Evaluator

When a person speaks, there are audible When a person speaks, there are audible voice frequencies and superimposed on these voice frequencies and superimposed on these are the inaudible frequency modulations are the inaudible frequency modulations which are products of minute oscillation of which are products of minute oscillation of the muscles of the voice mechanism. Such the muscles of the voice mechanism. Such oscillations of the muscles micro tremor oscillations of the muscles micro tremor occur at the rate of 8 to 14 cycles per second occur at the rate of 8 to 14 cycles per second and controlled by the central nervous and controlled by the central nervous system.system.

When the person is under stress as when he When the person is under stress as when he is lying, the micro tremor in the voice is lying, the micro tremor in the voice utterance in moderately or completely utterance in moderately or completely suppressed.suppressed.

The degree of suppression caries inversely The degree of suppression caries inversely to the degree of psychologic stress in the to the degree of psychologic stress in the speaker.speaker.

The psychological stress evaluator (PSE) The psychological stress evaluator (PSE) detects, measures, and graphically displays detects, measures, and graphically displays the voice modulations that we cannot hear.the voice modulations that we cannot hear.

When a person is relaxed and responding When a person is relaxed and responding honestly to the questions, those inaudible honestly to the questions, those inaudible frequencies are registered clearly on th frequencies are registered clearly on th instrument. But when a person is under instrument. But when a person is under stress, as when he is lying, these stress, as when he is lying, these frequencies tend to disappear.frequencies tend to disappear.

Procedure:Procedure:

The examiner meets the requesting party to The examiner meets the requesting party to determine the specific purpose of the determine the specific purpose of the examination and to begin formulation of examination and to begin formulation of relevant questions.relevant questions.

A pre-test interview is conducted with the A pre-test interview is conducted with the subject to help him or her feel at ease with the subject to help him or her feel at ease with the examiner, to provide an opportunity to specify examiner, to provide an opportunity to specify matters, to eliminate outside issues, and to matters, to eliminate outside issues, and to review questions that will be asked.review questions that will be asked.

An roal test of about 12 to 15 “yes” or “no” An roal test of about 12 to 15 “yes” or “no” questions or given which is recorded on a tape questions or given which is recorded on a tape recorder. The questions are a mixture of recorder. The questions are a mixture of relevant and irrelevant questions.relevant and irrelevant questions.

Immediately following the test or at a later Immediately following the test or at a later time, the tape is processed through the time, the tape is processed through the Psychological Stress Evaluator for analysis of Psychological Stress Evaluator for analysis of the answers.the answers.

If stress is indicated, the subject is given If stress is indicated, the subject is given opportunity to provide additional clarification. opportunity to provide additional clarification. A retest is given to verify correction and A retest is given to verify correction and clarification.clarification.

Use of Drugs that “Inhibit the Use of Drugs that “Inhibit the Inhibitor”Inhibitor”

Administration of the TRUTH SERUMAdministration of the TRUTH SERUM Narcoanalysis/NarcosysthesisNarcoanalysis/Narcosysthesis Intoxication with AlcoholIntoxication with Alcohol

TRUTH SERUMTRUTH SERUM

The term “ truth serum” is a misnomer. The The term “ truth serum” is a misnomer. The procedure does not make someone tell the procedure does not make someone tell the truth and the thing administered is not serum truth and the thing administered is not serum but actually a drug.but actually a drug.

In the test, HYOSCINE HYDROBROMIDE is In the test, HYOSCINE HYDROBROMIDE is given hypodermically in repeated doses until a given hypodermically in repeated doses until a state of delirium is induced.state of delirium is induced.

When the proper point is reached, the When the proper point is reached, the questioning begins and the subject fells a questioning begins and the subject fells a compulsion to answer the questions truthfully.compulsion to answer the questions truthfully.

He forgets his alibi which he may have built He forgets his alibi which he may have built up to cover his guilt. He may give details of up to cover his guilt. He may give details of his acts or may even implicate others.his acts or may even implicate others.

The drug acts as depressant in the nervous The drug acts as depressant in the nervous system. Clinical evidence indicates the various system. Clinical evidence indicates the various segments of the brain particularly the cortex.segments of the brain particularly the cortex.

Statements taken from the subjects while Statements taken from the subjects while under the influence of truth serum are under the influence of truth serum are evolutionary obtained hence they are not evolutionary obtained hence they are not admissible as evidence.admissible as evidence.

Narcoanalysis/NarcosynthesisNarcoanalysis/Narcosynthesis

This method of deception detection is This method of deception detection is practically the same as that of administration practically the same as that of administration of truth serum. The only difference is the drug of truth serum. The only difference is the drug used. used. Psychiatric sodium amytal or sodium Psychiatric sodium amytal or sodium penthotal penthotal is administered by the subject.is administered by the subject.

When the effects appear , questioning starts.When the effects appear , questioning starts. It is claimed that the drug causes depression of It is claimed that the drug causes depression of

the inhibitory mechanism of the brain and the the inhibitory mechanism of the brain and the subjects talk freely.subjects talk freely.

The administration of the drug and The administration of the drug and subsequent interrogation must be done by subsequent interrogation must be done by a psychiatrist with along experience on a psychiatrist with along experience on the line.the line.

Like the administration of the truth Like the administration of the truth serum, the result of the test is not serum, the result of the test is not admissible.admissible.

INTOXICATIONINTOXICATION

The apparent stimulation effect of alcohol The apparent stimulation effect of alcohol is really the result of the control is really the result of the control mechanism of the brain. The apparent mechanism of the brain. The apparent stimulation effect of alcohol is really the stimulation effect of alcohol is really the result of the control mechanism of the result of the control mechanism of the brain, so alcohol, like truth serum and brain, so alcohol, like truth serum and narcoanalysis drugs “inhibit the narcoanalysis drugs “inhibit the inhibitor”.inhibitor”.

The ability of alcohol to reveal the real The ability of alcohol to reveal the real person behind the mask which all of us person behind the mask which all of us are said to wear (“mask of sanity’) is are said to wear (“mask of sanity’) is reflected in the age-old maxim,reflected in the age-old maxim, IN VINO IN VINO VERITAS VERITAS (“in wine there is truth”). (“in wine there is truth”).

The person whose statement is to be The person whose statement is to be taken is allowed to take alcoholic taken is allowed to take alcoholic beverages to almost intoxication.beverages to almost intoxication.

Confessions made by the subjects while Confessions made by the subjects while under the influence of alcohol may be under the influence of alcohol may be admissible if he is physically capable to admissible if he is physically capable to recollect the facts that he has uttered after recollect the facts that he has uttered after the effects of alcohol have disappeared.the effects of alcohol have disappeared.

But in most intances, the subjects cannot But in most intances, the subjects cannot recall everything that he had mentioned recall everything that he had mentioned or he may refuse to admit the truth of the or he may refuse to admit the truth of the statement given.statement given.

The knowledge of the truth is an The knowledge of the truth is an essential requirement for the essential requirement for the administration of criminal justice. The administration of criminal justice. The success or failure in making decisions success or failure in making decisions may rest solely on the ability to evaluate may rest solely on the ability to evaluate the truth or falsity of the statement given the truth or falsity of the statement given by the suspects or witness. The task for by the suspects or witness. The task for its determination initially lies on the its determination initially lies on the hand of the investigator.hand of the investigator.

HYPNOSISHYPNOSIS

It is the alteration of consciousness and It is the alteration of consciousness and concentration in which the subject concentration in which the subject manifests a heightened of suggestibility manifests a heightened of suggestibility while awareness is maintained.while awareness is maintained.

Not all persons are susceptible to hypnotic Not all persons are susceptible to hypnotic induction. Subjects who are compulsive-induction. Subjects who are compulsive-depressive type, strong-willed like lawyers, depressive type, strong-willed like lawyers, accountants, physicians and other accountants, physicians and other professionals are usually non-hypnotizable.professionals are usually non-hypnotizable.

REASONS: (why it is not admissible REASONS: (why it is not admissible in court)in court) It lacks the general scientific acceptance It lacks the general scientific acceptance

of the reliability of hypnosis per se in of the reliability of hypnosis per se in ascertaining the truth from falsity.ascertaining the truth from falsity.

The fear that the Trier of fact will give The fear that the Trier of fact will give uncritical and absolute reliability to a uncritical and absolute reliability to a scientific device without consideration of scientific device without consideration of its flaw in ascertaining veracity.its flaw in ascertaining veracity.

The possibility that the hypnotized subject will The possibility that the hypnotized subject will deliberately fabricate.deliberately fabricate.

The prospect that the state of heightened The prospect that the state of heightened suggestibility in which the hypnotized subject suggestibility in which the hypnotized subject is suspected will produce distortion of the fact is suspected will produce distortion of the fact rather than the truth.rather than the truth.

The state of the mind, skill and The state of the mind, skill and professionalism of the examiner are too professionalism of the examiner are too subjective to permit admissibility of the expert subjective to permit admissibility of the expert testimony.testimony.

Physiological Physiological &&

Psychological Symptoms Psychological Symptoms of of

GUILTGUILT

SWEATING- sweating accompanied with a flushed SWEATING- sweating accompanied with a flushed face indicate anger, embarrassment or extreme face indicate anger, embarrassment or extreme nervousness. Sweating with a palled face may indicate nervousness. Sweating with a palled face may indicate shock of fear. Sweating hands indicate tension.shock of fear. Sweating hands indicate tension.

COLOR CHANGE – if the face is flushed, it may COLOR CHANGE – if the face is flushed, it may indicate anger, embarrassment or shame. A pale face indicate anger, embarrassment or shame. A pale face is a more common sign of guilt.is a more common sign of guilt.

DRYNESS OF THE MOUTH – nervous tension DRYNESS OF THE MOUTH – nervous tension causes reflex inhibition of salivary secretion and causes reflex inhibition of salivary secretion and consequently dryness of the mouth. This causes consequently dryness of the mouth. This causes continuous swallowing and licking of the lips.continuous swallowing and licking of the lips.

Excessive activity of the Adam’s appleExcessive activity of the Adam’s apple - on - on account of the dryness of the throat aside from account of the dryness of the throat aside from the mouth, the subject will swallow saliva the mouth, the subject will swallow saliva from the mouth and this causes the frequent from the mouth and this causes the frequent upward and downward movement of the upward and downward movement of the Adam’s apple.Adam’s apple.

Fidgeting Fidgeting – subject is constantly moving about – subject is constantly moving about in the chair, pulling his ears, rubbing his face, in the chair, pulling his ears, rubbing his face, picking and tweaking the nose, crossing or picking and tweaking the nose, crossing or uncrossing the legs, rubbing the hair, eyes, uncrossing the legs, rubbing the hair, eyes, eyebrows, biting or snapping of fingernails. eyebrows, biting or snapping of fingernails. These are indicators of nervous tension.These are indicators of nervous tension.

Peculiar Feeling Inside Peculiar Feeling Inside – there is a sensation – there is a sensation of lightness of the head and the subject is of lightness of the head and the subject is confused. This is the result of his troubled confused. This is the result of his troubled conscience.conscience.

Swearing to the truthfulness of his assertionSwearing to the truthfulness of his assertion – – usually a guilty subject frequently utters such usually a guilty subject frequently utters such expression. “I swear to God I am telling the expression. “I swear to God I am telling the truth” or “ I hope my mother drops dead if I truth” or “ I hope my mother drops dead if I am lying”, “I swear to Go”…etc. Such am lying”, “I swear to Go”…etc. Such expressions are make to make forceful and expressions are make to make forceful and convincing his assertion of innocence.convincing his assertion of innocence.

Spotless past recordSpotless past record - “Religious man” – the - “Religious man” – the subject may assert that it is not possible for subject may assert that it is not possible for him to do “anything like that” inasmuch as he him to do “anything like that” inasmuch as he is a religious man and that he has a spotless is a religious man and that he has a spotless record.record.

Inability to look at the investigator “straight in Inability to look at the investigator “straight in the eye”the eye” – the subject does not like to look at – the subject does not like to look at the investigator for fear that his guilt may seen the investigator for fear that his guilt may seen in his eyes. He will rather look at the floor or in his eyes. He will rather look at the floor or ceiling.ceiling.

““Not that I remember” expression Not that I remember” expression – – the subject will resort to the use of the subject will resort to the use of “Not that I Remember” expression “Not that I Remember” expression when answering to be evasive or to when answering to be evasive or to avoid committing something avoid committing something prejudicial to him.prejudicial to him.

LIELIE

Is also called PREVARICATIONIs also called PREVARICATION A type of deception in the form of an A type of deception in the form of an

untruthful statement with the intention to untruthful statement with the intention to deceive, often with further intention to deceive, often with further intention to maintain a secret of reputation, to protect maintain a secret of reputation, to protect someone’s feelings from getting hurt, or to someone’s feelings from getting hurt, or to avoid punishment.avoid punishment.

Classification of LiesClassification of Lies

Bald-Faced lieBald-Faced lie

A bald-faced ( or barefaced) lie is a lie A bald-faced ( or barefaced) lie is a lie that is told when it is obvious to all that is told when it is obvious to all concerned that is it a lie.concerned that is it a lie.

Example: a child who has chocolate all Example: a child who has chocolate all over his face and denies that he has eaten over his face and denies that he has eaten the last piece of chocolate cake, is a bald-the last piece of chocolate cake, is a bald-face liar.face liar.

Lying by omissionLying by omission

One lies by omission by omitting an One lies by omission by omitting an important fact, deliberately leaving important fact, deliberately leaving another person with a misconception. another person with a misconception. Lying by omission includes failures Lying by omission includes failures to correct pre-existing to correct pre-existing misconceptions.misconceptions.

Lie-to-childrenLie-to-children

A lie-to-children is a lie, often a A lie-to-children is a lie, often a platitude that may use euphemism, platitude that may use euphemism, that is told to make an adult subject that is told to make an adult subject acceptable to children. A common acceptable to children. A common example is “ The stork brought you”.example is “ The stork brought you”.

White lieWhite lie

A white lie would cause no discord if it were A white lie would cause no discord if it were uncovered and offers some benefit to the liar, uncovered and offers some benefit to the liar, the hearer, or both.the hearer, or both.

White lies are often used to avoid offense, such White lies are often used to avoid offense, such as telling someone that you think that their new as telling someone that you think that their new outfit looks good when you actually think that it outfit looks good when you actually think that it is a horrible excuse for an outfit.is a horrible excuse for an outfit.

The lie is told to avoid the harmful implications The lie is told to avoid the harmful implications and realistic implications of the truth.and realistic implications of the truth.

NOBLE LIENOBLE LIE

A noble lie is one that would normally cause A noble lie is one that would normally cause discord it if were uncovered, but that offers discord it if were uncovered, but that offers some benefit to the liar and perhaps assist in some benefit to the liar and perhaps assist in an orderly society and thus potentially gives an orderly society and thus potentially gives some benefit to others also.some benefit to others also.

It is often told to maintain law, order and It is often told to maintain law, order and safety.safety.

A noble lie usually has the effect of helping an A noble lie usually has the effect of helping an elite maintain power.elite maintain power.

EMERGENCY LIEEMERGENCY LIE

An emergency lie is a strategic lie told when An emergency lie is a strategic lie told when the truth may not be told because, for example, the truth may not be told because, for example, harm to a third party would come of it.harm to a third party would come of it.

Example: a neighbor might lie to an engaged Example: a neighbor might lie to an engaged husband about the whereabouts of his husband about the whereabouts of his unfaithful wife, because said husband might unfaithful wife, because said husband might reasonably be expected to inflict physical reasonably be expected to inflict physical injury to his husband.injury to his husband.

PERJURYPERJURY

It is the act of lying or making verifiably false It is the act of lying or making verifiably false statements on an material matter under oath or statements on an material matter under oath or affirmation in a court of law or in any of affirmation in a court of law or in any of various sworn statements in writing.various sworn statements in writing.

Perjury is a crime because the witness has Perjury is a crime because the witness has sworn to tell the truth and, for the credibility of sworn to tell the truth and, for the credibility of the court, witness testimony must be relied on the court, witness testimony must be relied on an being truthful.an being truthful.

BLUFFINGBLUFFING

Pretending to have capability or intention one Pretending to have capability or intention one doesn’t. Bluffing is an act of deception that is doesn’t. Bluffing is an act of deception that is not usually seen as immoral because it takes not usually seen as immoral because it takes place in the context of a game where this kind place in the context of a game where this kind of deception is consented to in advance by the of deception is consented to in advance by the players.players.

MISLEADINGMISLEADING

A misleading statement is one where there A misleading statement is one where there isn’t an outright lie, but still has the purpose of isn’t an outright lie, but still has the purpose of making someone believe in an untruth.making someone believe in an untruth.

DISSEMBLINGDISSEMBLING

A polite term for lying, though some might A polite term for lying, though some might consider it to refer to being merely misleading.consider it to refer to being merely misleading.

It is merely considered to be a euphemism for It is merely considered to be a euphemism for lying.lying.

EXAGGERATIONEXAGGERATION

An exaggeration occurs when the most An exaggeration occurs when the most fundamental aspect of a statement is true, but fundamental aspect of a statement is true, but the degree to which it is true is not correct.the degree to which it is true is not correct.

JOCOSE LIEJOCOSE LIE

Are lies that are meant in jest and are usually Are lies that are meant in jest and are usually understood as such by all present parties.understood as such by all present parties.

Sarcasm can be an example.Sarcasm can be an example. Storytelling traditions that are present in some Storytelling traditions that are present in some

places, where the humor comes form the places, where the humor comes form the storyteller’s insistence that he or she is telling storyteller’s insistence that he or she is telling that absolute truth despite all evidence to the that absolute truth despite all evidence to the contrary.contrary.

PROMOTION LIESPROMOTION LIES

Advertisements often contain statements that Advertisements often contain statements that are not credible, such as “we are always happy are not credible, such as “we are always happy to give a refund.”to give a refund.”

BELIEF SYSTEMSBELIEF SYSTEMS

It is alleged that some belief systems may find It is alleged that some belief systems may find lying to be justified.lying to be justified.

Example: Religious liesExample: Religious lies

Augustine’s Taxonomy of LiesAugustine’s Taxonomy of Lies

Lies in religious teaching.Lies in religious teaching. Lies that harm others and help no one.Lies that harm others and help no one. Lies that harm others and help someone.Lies that harm others and help someone. Lies told for the pleasure of lyingLies told for the pleasure of lying Lies told “please others in smooth discourse”.Lies told “please others in smooth discourse”. Lies that harm no one and that help someone.Lies that harm no one and that help someone. Lies that harm no one and that save someone’s life.Lies that harm no one and that save someone’s life. Lies that harm no one and that save someone’s purity.Lies that harm no one and that save someone’s purity.

Lying in the bibleLying in the bible

The Hebrew midwives lied to the king of The Hebrew midwives lied to the king of Egypt rather than carry out his order to kill all Egypt rather than carry out his order to kill all male Hebrew babies; the midwives did this male Hebrew babies; the midwives did this because they “feared God” . (Exodus 1:15-20)because they “feared God” . (Exodus 1:15-20)

Rehab lied to the king of Jericho about hiding Rehab lied to the king of Jericho about hiding the Hebrew spies (Joshua 2:4-5) and was not the Hebrew spies (Joshua 2:4-5) and was not killed with those were disobedient because of killed with those were disobedient because of her faith (Hebrews 11:13)her faith (Hebrews 11:13)

Delilah repeatedly accused Samson of lying to Delilah repeatedly accused Samson of lying to her (Jg. 16:10-13) as she interrogated him her (Jg. 16:10-13) as she interrogated him about the source of his strength.about the source of his strength.

Abaraham instructs his wife, Sarai, to lie to the Abaraham instructs his wife, Sarai, to lie to the Egyptians and say that she is his sister (Gen Egyptians and say that she is his sister (Gen 12:10), which leads to the Lord punishing the 12:10), which leads to the Lord punishing the Egyptians (Gen 12:17-19).Egyptians (Gen 12:17-19).

Consequences of LyingConsequences of Lying

Discovered – discovery of lie tends to discredit Discovered – discovery of lie tends to discredit other statements by the same speaker and can other statements by the same speaker and can lead to social and legal sanctions againsts the lead to social and legal sanctions againsts the speaker.speaker.

Remain Undiscovered – undiscovered lie is a Remain Undiscovered – undiscovered lie is a latent danger to the liar who us probably aware latent danger to the liar who us probably aware that it may be discovered.that it may be discovered.

Representations of LyingRepresentations of Lying

Carlo Collodi’s Carlo Collodi’s PINOCCHIOPINOCCHIO is a wooden is a wooden puppet often led into trouble by his propensity puppet often led into trouble by his propensity to lie. His nose grows with every lie. A long to lie. His nose grows with every lie. A long nose has thus become a caricature of liars.nose has thus become a caricature of liars.

In the film In the film LIAR LIARLIAR LIAR, the lawyer Fletcher , the lawyer Fletcher Reed (Jim Carrey) cannot lie for 24 hours due Reed (Jim Carrey) cannot lie for 24 hours due to a wish of his son which magically came to a wish of his son which magically came true.true.

In 1985 MAX In 1985 MAX HEADROOMHEADROOM, the title , the title character comments that one can always tell character comments that one can always tell when a politician lies because ‘their lips when a politician lies because ‘their lips move”. The joke has been widely repeated and move”. The joke has been widely repeated and rephrased.rephrased.

In the film In the film BIG FAT LIAR, BIG FAT LIAR, the story which the story which producer Marty Wolf, a notorious and proud producer Marty Wolf, a notorious and proud liar himself. Each lie he tells causes him to liar himself. Each lie he tells causes him to grow in size.grow in size.

POLYGRAPHYPOLYGRAPHY

The science of Lie DetectionThe science of Lie Detection

The Polygraph Instrument The Polygraph Instrument

The polygraph instrument usually measures The polygraph instrument usually measures four to six physiological reactions recorded by four to six physiological reactions recorded by three different medical instruments that are three different medical instruments that are combined in one machine. Older polygraph combined in one machine. Older polygraph machines were equipped with long strips of machines were equipped with long strips of paper that moved slowly beneath pens that paper that moved slowly beneath pens that recorded the various physiological responses. recorded the various physiological responses. Newer equipment uses transducers to convert Newer equipment uses transducers to convert the information to digital signals that can be the information to digital signals that can be stored on computers and analyzed using stored on computers and analyzed using sophisticated mathematical algorithms.sophisticated mathematical algorithms.

CARDIO-SPHYGMOGRAPHCARDIO-SPHYGMOGRAPH

Blood pressure and heart rate are Blood pressure and heart rate are measured by the cardio-sphygmograph measured by the cardio-sphygmograph component of the polygraph, which component of the polygraph, which consists of a blood pressure cuff that is consists of a blood pressure cuff that is wrapped around the subject's arm.wrapped around the subject's arm.

During the questioning the cuff remains During the questioning the cuff remains inflated.inflated.

The movement of blood through the The movement of blood through the subject's veins generates a sound that subject's veins generates a sound that is transmitted through the air in the is transmitted through the air in the cuff to a bellows that amplifies the cuff to a bellows that amplifies the sound. The magnitude of the sound sound. The magnitude of the sound relates to the blood pressure and the relates to the blood pressure and the frequency of the changes in the frequency of the changes in the sound relates to the heart rate.sound relates to the heart rate.

PNEUMOGRAPH COMPONENTPNEUMOGRAPH COMPONENT

The pneumograph component of the The pneumograph component of the polygraph records the subject's polygraph records the subject's respiratory rate. One tube is placed respiratory rate. One tube is placed around the subject's chest and a second is around the subject's chest and a second is placed around his or her abdomen. These placed around his or her abdomen. These tubes are filled with air. When the subject tubes are filled with air. When the subject breaths, changes in the air pressure in the breaths, changes in the air pressure in the tubes are recorded on the polygraph.tubes are recorded on the polygraph.

GALVANOGRAPHGALVANOGRAPH

The galvanograph section records the The galvanograph section records the amount of perspiration produced. amount of perspiration produced.

It consists of electrical sensors called It consists of electrical sensors called galvanometers that are attached to the galvanometers that are attached to the subject's fingertips. The skin of the subject's fingertips. The skin of the fingertips contains a high density of fingertips contains a high density of sweat glands, making them a good sweat glands, making them a good location to measure perspiration.location to measure perspiration.

As the amount of sweat touching the As the amount of sweat touching the galvanometers increases, the resistance of galvanometers increases, the resistance of the electrical current measured decreases the electrical current measured decreases and these changes are recorded by the and these changes are recorded by the polygraph.polygraph.

Most forensic psychophysiologists (FPs) Most forensic psychophysiologists (FPs) consider the cardiosphygomgraph and the consider the cardiosphygomgraph and the pneumograph components more pneumograph components more informative than the galvanograph.informative than the galvanograph.

KEYMOGRAPHKEYMOGRAPH

Keymograph component is a motor Keymograph component is a motor that pulls or drives the chart paper that pulls or drives the chart paper under the recording pen under the recording pen simultaneously at the rate of 6 or 12 simultaneously at the rate of 6 or 12 inches per minute.inches per minute.

The Examination RoomThe Examination Room It must be private and free from all outside noise and It must be private and free from all outside noise and

detracting influences.detracting influences. Adequately lighted and well ventilatedAdequately lighted and well ventilated Devoid of pictures, paintings, decors or other Devoid of pictures, paintings, decors or other

ornaments.ornaments. Preferably sound-proofPreferably sound-proof Without any furniture other than a polygraph desk.Without any furniture other than a polygraph desk. Subjects chair with arm rest and an examiner’s stool.Subjects chair with arm rest and an examiner’s stool. With one-way mirror and remote sound system for With one-way mirror and remote sound system for

monitoring the test proceedings to an authorized monitoring the test proceedings to an authorized audience.audience.

The polygraph examinerThe polygraph examiner

TECHNICALLY, he must have a TECHNICALLY, he must have a complete knowledge of the instrument complete knowledge of the instrument and its capabilities and limitations.and its capabilities and limitations.

MORALLY – maintain a high personal MORALLY – maintain a high personal integrity and increasing personal integrity and increasing personal proficiency through constant study and proficiency through constant study and research.research.

He constantly bears in mind his primary He constantly bears in mind his primary obligation to his subjects is to afford them obligation to his subjects is to afford them all possible safeguards against error and all possible safeguards against error and must not accept any subjects whose must not accept any subjects whose physical or mental health or state makes physical or mental health or state makes him unfit.him unfit.

He is an impartial seeker of truth.He is an impartial seeker of truth. Never allow his personal feelings, Never allow his personal feelings,

sympathies, or prejudice influence the sympathies, or prejudice influence the results of the examination.results of the examination.

Selection of Test SubjectSelection of Test Subject Permanent physical illness such as mental Permanent physical illness such as mental

derangement, certain heart condition, breathing derangement, certain heart condition, breathing disorder, and addiction to narcotic drugs are definite disorder, and addiction to narcotic drugs are definite causes that makes a person unfit for a polygraph test.causes that makes a person unfit for a polygraph test.

Temporary illness and conditions such as sickness, Temporary illness and conditions such as sickness, injury, pain, physical discomfort, external physical or injury, pain, physical discomfort, external physical or mental fatigue, colds, coughs, fever, allergies, and mental fatigue, colds, coughs, fever, allergies, and influences of sedatives and liquor are causes for influences of sedatives and liquor are causes for deferment of the test until such time that the subjects deferment of the test until such time that the subjects regains his ordinary physical condition.regains his ordinary physical condition.

Treatment of the subjects before being asked Treatment of the subjects before being asked to make or while awaiting test affects the to make or while awaiting test affects the success of the examination.success of the examination.

Prolonged interrogation with constant Prolonged interrogation with constant accusation directed against the subjects may accusation directed against the subjects may condition him to react falsely to the test, or condition him to react falsely to the test, or may result to a flat emotionless chart.may result to a flat emotionless chart.

A person’s daily habit should not be upset A person’s daily habit should not be upset more than necessary. Long delay should be more than necessary. Long delay should be avoided.avoided.

PHASES of EXAMINATIONPHASES of EXAMINATION

PRE-TEST INTERVIEWPRE-TEST INTERVIEW ACTUAL interrogation and ACTUAL interrogation and

recording through the recording through the instrumentinstrument

POST-TEST INTERVIEWPOST-TEST INTERVIEW

Initial Interview with the Initial Interview with the InvestigatorInvestigator

Test question are formulated by the Test question are formulated by the polygraph examiner based from polygraph examiner based from information obtained from the investigator. information obtained from the investigator. General facts, theories and suspicions are General facts, theories and suspicions are not enough basis for a polygraph test. not enough basis for a polygraph test. Question formulation depends greatly Question formulation depends greatly upon detailed and accurate information upon detailed and accurate information regarding all the available facts.regarding all the available facts.

The investigator on case should personally inform the The investigator on case should personally inform the examiner of such facts as:examiner of such facts as:

Unpublicized facts of the offense known only Unpublicized facts of the offense known only to the victim, the investigator and the offender.to the victim, the investigator and the offender.

Specific articles or exact amounts of money Specific articles or exact amounts of money stolen.stolen.

Exact time and place the offense occurred.Exact time and place the offense occurred. Peculiar aspects of the offense or any strange Peculiar aspects of the offense or any strange

or obscene acts committed at the scene.or obscene acts committed at the scene.

Known facts about a suspects action or Known facts about a suspects action or movements immediately preceding of after the movements immediately preceding of after the incidents.incidents.

Facts indicating a connection between Facts indicating a connection between suspects, victims and witnesses, especially suspects, victims and witnesses, especially when they deny any connection.when they deny any connection.

Exact type of firearm, weapon or tool used.Exact type of firearm, weapon or tool used. Results of laboratory test if any.Results of laboratory test if any. Background information particularly previous Background information particularly previous

police records or verifies facts which subjects police records or verifies facts which subjects denies.denies.

PRE-TEST INTERVIEWPRE-TEST INTERVIEW Before the actual testing is done, the examiner Before the actual testing is done, the examiner

must first make an informal interview of the must first make an informal interview of the

subject which may last from 20 to 30 minutessubject which may last from 20 to 30 minutes.. To condition the subject psychologically for the To condition the subject psychologically for the

test.test. The subject is appraised of his constitutional The subject is appraised of his constitutional

rights.rights. A written consent which must be freely and A written consent which must be freely and

voluntary given is taken.voluntary given is taken.

Purpose of the Pre-Test InterviewPurpose of the Pre-Test Interview

To determine whether the subject has any To determine whether the subject has any medical or psychiatric condition or has used medical or psychiatric condition or has used drugs that will prevent the testing.drugs that will prevent the testing.

To explain to the subject the purpose of the To explain to the subject the purpose of the examination.examination.

To develop the test questions, particularly To develop the test questions, particularly those of the types to be asked.those of the types to be asked.

To relieve the truthful subject of any To relieve the truthful subject of any apprehension as well as to satisfy the apprehension as well as to satisfy the deceptive subject as to the efficiency deceptive subject as to the efficiency of the technique.of the technique.

To know any anti-social activity or To know any anti-social activity or criminal record of the subject.criminal record of the subject.

Question FormulationQuestion Formulation

Questions formulated are short, simple Questions formulated are short, simple and direct answerable by either ‘Yes” or and direct answerable by either ‘Yes” or “No” only, phrased in the language easily “No” only, phrased in the language easily understood by the subjects.understood by the subjects.

The questions must be clear and must The questions must be clear and must have reference to only one element of an have reference to only one element of an offense of fact.offense of fact.

Types of questionTypes of question

IRRELEVANTIRRELEVANTRELEVANTRELEVANTCONTROLCONTROL

IRRELEVANT QUESTIONSIRRELEVANT QUESTIONS

These are questions which have no bearing to These are questions which have no bearing to the case under investigation.the case under investigation.

The question may refer to the subject’s age, The question may refer to the subject’s age, educational attainment, marital status, educational attainment, marital status, citizenship, occupation, etc.citizenship, occupation, etc.

The examiner asks these types of questions to The examiner asks these types of questions to ascertain the subject’s normal pattern of ascertain the subject’s normal pattern of response by eliminating the feeling of response by eliminating the feeling of apprehension.apprehension.

RELEVANT QUESTIONSRELEVANT QUESTIONS

These are questions pertaining to the issue These are questions pertaining to the issue under investigation. They must be under investigation. They must be unambiguous, unequivocal and unambiguous, unequivocal and understandable to the subject.understandable to the subject.

They must be related to one issue or one They must be related to one issue or one criminal act.criminal act.

It is equally important to limit the number It is equally important to limit the number of relevant questions to avoid discomfort of relevant questions to avoid discomfort to the subject.to the subject.

Control QuestionsControl Questions

These are questions which are These are questions which are unrelated to the matter under unrelated to the matter under investigation but are of similar nature investigation but are of similar nature although less serious as compared to although less serious as compared to those relevant questions under those relevant questions under investigation.investigation.

Test Construction applied are of two Test Construction applied are of two main types.main types.

General Peak Tension TestGeneral Peak Tension Test Peak of Tension TestPeak of Tension Test

General Peak Tension TestGeneral Peak Tension Test

The general question test consist of a The general question test consist of a series of relevant and irrelevant series of relevant and irrelevant questioned asked in a planned order. questioned asked in a planned order.

Example:Example:

1.1. Have you ever been called by the name Have you ever been called by the name Fred? (Irrelevant)Fred? (Irrelevant)

2.2. Is today Friday? (Irrelevant)Is today Friday? (Irrelevant)

Do you have anything to do with the robbery Do you have anything to do with the robbery at Goodwill Grocery last night? (relevant)at Goodwill Grocery last night? (relevant)

Did you robbed the Goodwill Grocery last Did you robbed the Goodwill Grocery last night? (relevant)night? (relevant)

Are you over twenty years of age? (irrelevant)Are you over twenty years of age? (irrelevant) Do you know is any of the fingerprints found Do you know is any of the fingerprints found

at goodwill Grocery is yours? (relevant)at goodwill Grocery is yours? (relevant) Do you drink water? (Irrelevant)Do you drink water? (Irrelevant) Do you know of anyone involved in the Do you know of anyone involved in the

robbery of Goodwill Grocery last night? robbery of Goodwill Grocery last night? (Relevant)(Relevant)

Peak of Tension TestPeak of Tension Test

This valid test is only made when there is no This valid test is only made when there is no widespread publicity about the crime.widespread publicity about the crime.

Example:Example:

1.1. Do you know whether the stolen watch from Do you know whether the stolen watch from Fred is Boluva?Fred is Boluva?

2.2. It is an Elgin?It is an Elgin?

3.3. Is it a Colorado?Is it a Colorado?

4.4. Is it a Rolex?Is it a Rolex?

POST-TEST INTERROGATIONPOST-TEST INTERROGATION

To clarify the findingsTo clarify the findings To learn if there are any other reasons for the To learn if there are any other reasons for the

subject’s responding to a relevant question, subject’s responding to a relevant question, other than the knowledge of the crime.other than the knowledge of the crime.

To obtain additional information and an To obtain additional information and an admission for law enforcement purposes, if he admission for law enforcement purposes, if he results suggest deception.results suggest deception.

There are three basic approaches to There are three basic approaches to the polygraph test: the polygraph test:

The Control Question Test (CQT)The Control Question Test (CQT).. The Directed Lie Test (DLT)The Directed Lie Test (DLT).. The Guilty Knowledge Test (GKT)The Guilty Knowledge Test (GKT). .

The Control Question Test (CQT)The Control Question Test (CQT)

This test compares the physiological This test compares the physiological response to relevant questions about the response to relevant questions about the crime with the response to questions relating crime with the response to questions relating to possible prior misdeeds. "This test is often to possible prior misdeeds. "This test is often used to determine whether certain criminal used to determine whether certain criminal suspects should be prosecuted or classified suspects should be prosecuted or classified as uninvolved in the crime" (American as uninvolved in the crime" (American Psychological Association).Psychological Association).

The Directed Lie Test (DLT)The Directed Lie Test (DLT)

This test tries to detect lying by This test tries to detect lying by comparing physiological responses comparing physiological responses when the subject is told to when the subject is told to deliberately lie to responses when deliberately lie to responses when they tell the truth.they tell the truth.

The Guilty Knowledge Test (GKT)The Guilty Knowledge Test (GKT)

This test compares physiological This test compares physiological responses to multiple-choice type responses to multiple-choice type questions about the crime, one choice questions about the crime, one choice of which contains information only of which contains information only the crime investigators and the the crime investigators and the criminal would know about. criminal would know about.

ObjectivesObjectives

Ascertain if a person is telling the truth by Ascertain if a person is telling the truth by verifying statement and/or comparing verifying statement and/or comparing conflicting statements.conflicting statements.

Obtain additional investigative leads to the Obtain additional investigative leads to the facts of an offense.facts of an offense.

Locate fruits or roots of crime or Locate fruits or roots of crime or whereabouts of wanted persons.whereabouts of wanted persons.

Identify other persons involved.Identify other persons involved.

Obtain valuable information from Obtain valuable information from reluctant witnesses.reluctant witnesses.

Most important is the elimination of Most important is the elimination of innocent suspects.innocent suspects.

LimitationsLimitations

It is an invaluable investigation aid, but never It is an invaluable investigation aid, but never a substitute for investigation.a substitute for investigation.

It is a lie detector, it is not a scientific It is a lie detector, it is not a scientific diagnostic instrument.diagnostic instrument.

It does not determine facts, it records It does not determine facts, it records responses to that which the subject knows to responses to that which the subject knows to be true.be true.

It is only as accurate as the examiner is It is only as accurate as the examiner is competent.competent.

The underlying theory of the polygraph is that The underlying theory of the polygraph is that when people lie they also get measurably when people lie they also get measurably nervous about lying. The heartbeat increases, nervous about lying. The heartbeat increases, blood pressure goes up, breathing rhythms blood pressure goes up, breathing rhythms change, perspiration increases, etc. A baseline change, perspiration increases, etc. A baseline for these physiological characteristics is for these physiological characteristics is established by asking the subject questions established by asking the subject questions whose answers the investigator knows. whose answers the investigator knows. Deviation from the baseline for truthfulness is Deviation from the baseline for truthfulness is taken as sign of lying taken as sign of lying

Test ProcedureTest Procedure

Not more than 12 questionsNot more than 12 questions At least three (3) charts are taken, At least three (3) charts are taken,

each lasting not more than four (4) each lasting not more than four (4) minutes, minutes,

5 to ten minutes between charts.5 to ten minutes between charts.

Chart MarkingChart Marking

BeginningBeginning XX StimulusStimulus ““ YesYes ++ NoNo -- Subject fail to answerSubject fail to answer No signNo sign Subject TalkSubject Talk TT Talking Instruction Talking Instruction TITI CoughingCoughing CC

Chart MarkingChart Marking

Mechanical AdjustmentMechanical Adjustment ArrowArrow Tearing of throatTearing of throat CTCT Outside NoiseOutside Noise OSNOSN SighSigh SS SniffSniff SNSN SneezeSneeze SZSZ BURPBURP BB YAWNYAWN YY

Chart MarkingChart Marking

Deep breathingDeep breathing DBDB Subject LaughSubject Laugh LL Breathing InstructionBreathing Instruction BIBI Repeat QuestionRepeat Question RR Paper JumpPaper Jump PJPJ EndingEnding XXXX

Rule in InterpretationRule in Interpretation

There must be specific response hat There must be specific response hat deviates from the subjects’ normal deviates from the subjects’ normal tracing.tracing.

It must appear in at least two or more It must appear in at least two or more chartchart..

Thank you……….Thank you……….