The Use Of The Polygraph In The Community Supervision Of Sex Offenders
| Published date | 01 December 1999 |
| Date | 01 December 1999 |
| DOI | http://doi.org/10.1177/026455059904600403 |
| Subject Matter | Articles |
The Use Of The
Polygraph In The
Community Supervision
Of Sex Offenders
Encouraging disclosure of information is an essential task of
probation intervention with sex offenders. Here, Daniel Wilcox,
Dan Sosnowski and David Middleton argue that the polygraph, or lie
detector, can help to achieve this aim, and play an important role in
assessing risk, treating and managing sex offenders on probation or
licence. They examine the use of the polygraph in the USA, and give
some early reflections on the first UK
polygraph trial, held in the
West Midlands Probation Service area. The results suggest that
workers were able to obtain more detailed information about index
offences, further diclosures of past sexual offending, and more
information about short-term risk and non-compliance with
conditions of probation orders.
olygraphy has attracted significant reference in this regard (Wilcox, 1999 -
interest from practitioners working
submitted for publication - could also be a
with
sex
offenders,
though many
helpful source of information).
professionals in the UK
still require further
background information about what it is
and what it measures. This article addresses
What Is a Polygraph and
these issues and also presents information
.
concerning the accuracy, reliability, and
utility of polygraphy, as well as a discussion
A
polygraph
instrument
collects
of the implications for future practice.
physiological data from at least three
However, it is beyond the scope of this
systems
within
the
human
body.
paper to detail the development of
Convoluted rubber tubes are placed over
polygraphy or comprehensively review the
the examinee’s chest and abdominal area to
literature
concerning
its
specific
record respiratory activity. Two small metal
applications to sex offender work. Abrams
plates are attached to the fingers, to record
and Abrams (1993) may serve as a useful
sweat gland activity and a blood pressure
234
cuff
or
similar
device
records
in the United States, Canada, Israel, Japan
cardiovascular activity. A typical polygraph
and Poland&dquo;
examination will include a period referred
However,
while
the
polygraph
to as a pre-test interview, a chart collection
technique is highly accurate, it is not
phase and a test data analysis phase.
infallible and errors do occur. Polygraph
In the pre-test phase the polygraph
errors may be caused by a failure to
examiner
will
complete
required
properly prepare the examinee for the
paperwork and talk with the examinee
examination or by a misreading of the
about the test. During this period, the
physiological data on the polygraph charts.
examiner will discuss the questions to be
Adherence to established testing protocols
asked and familiarise the examinee with the
and
stringent
polygraph
training
testing procedure. A
range of information is
requirements are the best way to control for
then obtained in relation to each of the
these errors which are usually referred to as
physiological indices and research has
either ’false positive’ or ’false negative’. A
indicated that when a properly trained
’false positive’ error occurs when a truthful
examiner utilises an established testing
examinee is reported as being deceptive, a
procedure the accuracy of the decision
’false negative’ occurs when a deceptive
rnade by the polygraph examiner is
examinee is reported as being truthful.
generally above 90% (see below for
discussion and references).
The American Polygraph Association
has endorsed specific guidelines and
~~MNttNttttN~tN
procedures to identify the presence of
How Accurate is
factors, which may cause false responses,
and to ensure an unbiased review of the
polygraphy?
polygraph
records.
The
polygraph
examiner will ordinarily offer a finding of
In the past seventy-five years, over 250
Deception Indicated (DI), No Deception
studies have been conducted on the
Indicated (NDI) or an inconclusive result
accuracy of polygraph testing. Since many
which simply means that the polygraph
different conditions and factors are
examiner is unable to make a definite
involved in the research and since a
judgement. In this last eventuality, a second
polygraph examination is a very complex
examination is usually conducted at a later
process, it is difficult to draw from the data
date and in approximately 90% of those
a specific figure for the accuracy of
cases, the examiner is able to render an
polygraph testing in all settings. Ansley
opinion at that time.
(1990), investigated validity and reliability
A
number of protective procedures are
of polygraph testing, compiling the results
now incorporated into polygraph testing
of ten studies conducted between 1980 and
through the increasingly rigorous guidance
1990. He reported that:
given by the American Polygraph
&dquo;Examiner decisions in these studies,
Association...
To continue reading
Request your trial