Polygraph Unit

The Detective Sergeant of the Homicide Unit supervises the Polygraph Unit. The Polygraph Unit has three (3) detective examiners. Two (2) examiners are assigned to the Homicide Unit. The third examiner is assigned to the Child Abuse Unit. The polygraph is used as an investigative tool to assist Law Enforcement. Polygraph tests or examinations have been utilized in the investigation of various crimes such as: Arson, Theft, Homicide, Burglary and Child Abuse. The polygraph instrument measures three (3) body functions: breathing, blood pressure and sweating. A polygraph test or examination can only be administrated after the person to be tested has signed a Miranda Rights Waiver Form and a Polygraph Consent Form.

The polygraph test consists of the following:

  • Signing of the Rights and Consent Forms.
  • A pre-test interview of the examinee regarding personal, medical and miscellaneous data.
  • An explanation of how the polygraph works.
  • A review of the questions to be asked on the test by the examiner.
  • The test with the examinee’s reactions to the test questions.
  • The production of three (3) charts showing the examinee’s reactions to the test questions.

At the completion of the examination, the examiner reviews the charts and determines whether the examinee was truthful or deceptive or whether the test was inconclusive. The CID Polygraph Unit utilizes the Lafayette Computerized Polygraph Instrument. The instrument is continuously updated with new software.