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Value of the Polygraph Technique in a Serial Murder Investigation

NCJ Number
236809
Journal
Polygraph Volume: 40 Issue: 3 Dated: 2011 Pages: 157-165
Author(s)
Joseph R. Kozenczak; Karen M. Kozenczak
Date Published
2011
Length
9 pages
Annotation
The polygraph test that was administered to a co-worker of serial murderer John Wayne Gacy showed that in the investigative process the polygraph may not only result in providing conclusive test results, but may also succeed in bringing out valuable commentary during the pretest and posttest interviews.
Abstract
Although the polygraph examiner (one of the authors, Joseph R. Kozenczak) found that the polygraph examination of Gacy's associate was inconclusive, verbal information obtained during the pretest and posttest interviews proved invaluable. This information aided investigators in obtaining a second search warrant, which resulted in uncovering 28 bodies from under Gacy's Norwood Park Township home in December 1978. This article first provides background information on the "Reid Technique" (John E. Reid), who's most significant contribution to the field, was the use of probable-lie comparison questions in the structure of the polygraph examination process. The Reid Technique also includes an extensive pretest interview during which the subject is questioned about the case under investigation. All of the test questions are prepared and read to the subject prior to the testing phase of the examination; and the subject is asked a series of behavior-provoking questions. In the examination of Gacy's associate, 11 test questions were developed during the pretest interview. When these questions were asked in several different tests in which the sequence of the questions varied, the subject's respiration, electrodermal activity, pulse, and blood pressure were monitored by the polygraph. This article discusses the question formulation in detail and lists the 11 questions that were asked by the examiner. This is followed by a discussion of "deceptive parameters" in the examination. The author notes that the posttest interview was the most useful in guiding police to find Gacy's victims buried in the crawlspace under Gacy's house. 4 figures and 1 reference

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