Polygraph Page

            Hello my name is Troy Jerrell and I am the polygraph examiner for the Department. I spent months being trained in the use of the polygraph at the Backster School of Lie Detection. Afterward I spent over a year completing the field training exercises before I was completely finished with the training. I also am a licensed Examiner in the State of Indiana and am a member of the Indiana Polygraph Association. I am also certified through the Sauk Valley Community College to conduct Post Convicted Sex Offender Testing. The polygraph has been a big help for not only us but surrounding departments. I typically conduct as many test for neighboring departments as for the Linton Police Department. Several cases have been solved by utilizing this technology.

             The equipment used is the Lafayette Instrument manufactured here in the State of Indiana. Lafayette is one of the main manufactures of polygraph equipment in the world not just the US.

            I typically get several questions regarding the polygraph test so I will attempt to answer a few of them.

    Q: How long does the test take?

    A: Approximately 3 hours. However the examinee does not have attachments placed on them during that whole time frame. Most of the test consists of verbal interview and instructions.

    Q: I am a nervous type person, will this effect the results of my test?

    A: No it won't.

    Q: Can the results of the test be admissible in a court of law.

    A: Yes the test can be admissible under what is called a stipulated agreement. Stipulated simply means the examinee and the Prosecutor both sign a paper basically stating they agree for the results to be admissible.

    Q: How does the polygraph work?

    A: Magic, no just kidding. To put it simply the polygraph works of the connection between the mind and body that gives a physiological response. In other words the mind knows what you are saying is a lie or truth and will give off certain physiological responses. Some of those responses can be read and printed out on chart paper. A numeric system can then be placed on them and a decision can then be reached. 

     Q: Does anyone ever pass the polygraph test?

      A: Of course, my log shows that almost as many have passed the test as have failed. These numbers also correspond with many studies conducted. In fact some of the cases I have been involved in the suspect in the case has been cleared.   

I hope these answered some of your questions.