Detecting Deception

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Detecting Deception
Steven Van Aperen Australian Polygraph
Services 23rd November 2006
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All truths are easy to understand once they are
discovered the point is to discover them.
Galileo Galilei
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It is very difficult for the average person to
lie.
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Why do people deceive?

• Conditioning
• To hide the truth
• To protect themselves

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Types of lies

• I wasnt involved in match fixing, I always
  played to win
• I studied psychology at University
• I did not have have sexual relations with that
  woman Monica Lewinski?

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Lying in Employment

• One third admitted to lying on CV
• 47 lied about leisure pursuits
• 28 about their salary
• 19 about personal skills qualities
• 3 about criminal record

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Lying in Employment

• 18 think its necessary to lie on CVs
• One fifth believe employers dont check
• 6 say that they would just say they made a
  typing error!
• 30 admit to lying but managers think only one in
  ten (10) CVs contain false information
• 36 believe it is the responsibility of employers
  to check accuracy

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What to look for

• Paralinguistic Changes
• Non-Verbal (Body Language)
• Verbal (Lying with words)

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What to look for

• Tone
• Pitch
• Rate
• Response Latency

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Non-Verbal Behaviours

• Look for clusters of behaviour
• Be aware of hand to face gestures

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Non-Verbal Behaviours

• Research indicates that up to 80 of
  communication is non-verbal

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Non-Verbal Behaviours

• Remember our body language will often betray the
  spoken word.
• (Yes/No)

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The eyes have it, or do they?
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The Qualifying Statement
The subjects response may be literally true
because they deny some narrow issue of the
interviewers question
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Lying by generalisation
Often a person will lie by generalisation. This
occurs when a person may be vague or non-specific
in response to a question.
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Verbal Responses
Truthful people answer specific questions with
direct, spontaneous and realistic words
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Examples of how people deceive
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Analysing content and structure
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Police negotiator (PN) and Martin Bryant
(MB) 28th April, 2000 re Sally Martin
PN Theyre now with you are they? MB Yeah
Ive actually transported the female,
Sally. MB Um ah yes shes asl um shes half
asleep anyway
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Police negotiator (PN) and Martin Bryant
(MB) 28th April, 2000 re Sally Martin
PN Shed be very frightened and shes an
elderly lady. MB Yeah I got her upstairs
so PN So you can imagine that the trauma
that shes going through MB Shell be fine I
mean they could eat well
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Police negotiator (PN) and Martin Bryant
(MB) 28th April, 2000 re Sally Martin
PN Are you prepared to let me talk to Sally
MB Ah unfortunately um shes down stairs
with David now Ive got um another chap with
me.
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Past Present Tenses

• Singular person past tense vs present tense
• Look for changes between past and present tense

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• It was Monday night. I was walking down the road.
  It was getting dark when a man ran up and punched
  me in the face
• It was Monday night. I was walking down the road.
  It was getting dark and a man runs up and punches
  me in the face.

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Susan Smith 25th October, 1994
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• My children wanted me. They needed me. And now I
  cant help them. Susan Smith (mother)
• Theyre OK. Theyre going to be home soon.
  David Smith (father)

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Shapelle Corby

• I didn't put it there (4 times)
• This is not mine
• I'm innocent (twice)
• I didn't put it there thats the bottom line I
  didn't put it there.
• They're not my drugs. I didn't put them there.
• Im innocent.

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John Myles Sharpe plea for the return of Anna
Kemp Gracie Sharpe

• Did you kill your wife and daughter?
• I haven't harmed my wife or my daughter
• The child belongs with the mother

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Summary

• Learn to understand and read body language
• Are questions being answered or is the person
  being evasive, omissive or dismissive?
• Observe what the person is doing as well as
  listening to what they are saying

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Summary

• Look for changes between past and present tenses
• Look for clusters of behaviour
• Remember we lie by omission rather than
  commission
• PRACTICE!