Adjunct Techniques

Peak of Tension Tests

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• Introduction

  Peak of Tension (POT) tests have been used since the beginning of polygraphy, and continue to be helpful in some polygraph cases. For most polygraphers, the POT is conducted after a CQT has indicated deception, to confirm the finding or to help investigators search for evidence.

  There are two main types of POTs: Known Solution POT (KSPOT), and Searching POT (SPOT). POTs must be competently constructed and conducted to be of useful. This guide provides step-by-step instructions for the examiner who wishes to administer the proper POT.

• Terminology

  Cover-all question: Question used in the Searching Peak of Tension to determine whether the concealed information was not captured in the other possible keys.

  False key: A question sometimes placed in the Known Solution Peak of Tension to distract an innocent examinee.

  Known Solution Peak of Tension (KSPOT): Multiple-choice polygraph test in which the true item is known to investigators and the guilty examinee, but not the innocent examinee.

  Key: The item in the Peak of Tension test that relates to a detail of a crime that would only be recognized by the guilty person but not the innocent examinee.

  Padding: Items in the Searching Peak of Tension test that would be recognized by the guilty person as unrelated to the crime, and also would be seen by the innocent examinee as equally probable as the key.

  Possible keys: Items in the Searching Peak of Tension test that encompass crime details known to the guilty person, but not investigators. Used to reveal the location of evidence, names of accomplices, or other details of interest to investigators.

  Searching Peak of Tension (SPOT): Multiple-choice polygraph test in which the true key is known to the guilty examinee, but not to investigators. Uses padding and possible keys to probe for this information.

• Case Preparation

  For the Known Solution Peak of Tension test (KSPOT), the examiner knows the information, but the Searching Peak of Tension test (SPOT) is used to help uncover vital evidence not known to investigators. The first step for both applications is a review of the evidence. Below are potential sources of information for constructing the POT.

  • Police reports
  • Witness statements
  • Victim statements
  • Crime scene photos
  • Area maps
  • Forensic reports

• Construction

  KSPOTs

  1. The KSPOT always has from 6 to 9 items.
  2. There must be at least 2 padding questions before and after the key. If more than 1 KSPOT is conducted, the key to each test is placed in a different position than the other tests.
  3. Each key must be mutually exclusive of the other keys.
  4. The key must be a verified fact, and one that the guilty, and only the guilty, would recognize.
  5. Optional: The false key. An item may be placed in the second position of the test for which the examinee or examiner has placed special emphasis, but is not the true key.

  SPOTs

  1. The SPOT typically has about 9 to 10 items.
  2. It is constructed with 4 or 5 possible keys.
  3. There must be at least 2 padding questions before and after the possible keys. Padding questions must be impossible options, so that they do not become possible keys.
  4. The possible keys must be exhaustive and mutually exclusive, that is, all possibilities must be covered, but there must be no overlap among the keys.
  5. A cover-all question is recommended in case the true key is not among the possible keys.
  6. The examinee must recognize the true key.

• Conducting the POT

  1. Each test begins with a preparatory phrase that clearly states what the test covers, and which is used only once at the beginning of the test. For example: Regarding the type of weapon used to threaten Charlie Wilson...
  2. Each item is preceded by a standard phrase, such as was it, is that person, is it located in, etc. For example: Was it a knife? Was it a club? Was it a rifle? etc.
  3. The questions are always reviewed with the examinee before the test.
  4. The examinee answers "No" to all of the questions.
  5. Visual aids (i.e., maps, photos, diagrams, question list) should be placed in front of the examinee to augment the verbal presentation of the questions, especially with Searching Peak of Tension tests.
  6. Each POT is conducted at least 3 times, and questions are spaced 15-20 seconds apart. For the first 2 tests, the order of the questions are exactly as they were reviewed with the examinee before the test began. For the third test, the order is reversed, and the examinee is advised in advance. A fourth chart is permitted, with a mixed question order, if the first 3 do not result in a definite opinion.