7 Situations Where a Polygraph is a Valuable Tool

Since setting up Kendall Investigations in 2001, former FBI special agent Kendall Shull has been offering polygraph examinations in Knoxville, Tennessee, for a variety of different reasons. The polygraph, also commonly referred to as a lie detector, was initially developed to detect deception in criminal proceedings, but over the years, its use has become increasingly more mainstream in a variety of other situations, finding its way into the corporate world and even personal disputes. Let's take a look at some of the situations where polygraph examinations in Knoxville, Tennessee, have become a valuable tool in getting to the root of the truth!

1 - Criminal Investigations

Perhaps the most well-known application of polygraph examinations in Knoxville, Tennessee, is in criminal investigations. Law enforcement agencies are able to use polygraph tests to assist in narrowing down suspects, extracting confessions, and verifying statements. In fact, during his time with the FBI, Kendall Shull served as Chief of the Polygraph Program and had a significant role in investigating and prosecuting a number of major criminal cases both nationally and internationally. It is important to note that polygraphs are not admissible in court as irrefutable evidence; they are still a very useful tool that can guide an investigation down the right track. For example, law enforcement officials may turn their attention elsewhere if a suspect willingly submits to a polygraph exam and passes.

2 - Pre-Employment Screening

In the corporate world, polygraph examinations in Knoxville, Tennessee, are sometimes used as part of the pre-employment screening process, particularly for positions requiring high trust or security clearances. Candidates for jobs in law enforcement, government agencies, and sensitive industries may be subjected to polygraph examinations to ensure they do not pose a risk to the organization. Any time a polygraph examination in Knoxville, Tennessee, is conducted as part of employment pre-screening, it must be done per the Employee Polygraph Protection Act (EPPA), which prohibits most private employers from using lie detector tests. There are some exceptions; for example, private employers may use polygraph testing if they have reasonable suspicion of theft or embezzlement that has resulted in significant economic loss. Even in these situations, the test must follow strict guidelines set out by the EPPA.

3 - National Security and Intelligence

As we have touched on with Kendall Shull's history with the FBI, government agencies, such as the CIA and FBI, use polygraphs to assess the trustworthiness and reliability of individuals seeking access to classified information. This is crucial in maintaining the security and integrity of sensitive national data. Employees in positions of great responsibility and those handling classified information may be subject to regular polygraph tests.

4 - Probation and Parole Monitoring

Polygraph examinations in Knoxville, Tennessee, are employed in the criminal justice system to monitor individuals on probation or parole. By assessing the truthfulness of statements regarding compliance with court-ordered restrictions, authorities can better manage and ensure the safety of both the individual and the community.

5 - Civil Litigation

While not as common as in criminal cases, polygraph examinations in Knoxville, Tennessee, have also been used in civil litigation matters. In some instances, parties may agree to undergo a polygraph examination to bolster their credibility or resolve disputes, especially in cases where one party is being accused of deception.

6 - Infidelity and Relationship Issues

Private investigators and therapists will often make use of polygraph tests to address issues of trust and fidelity in personal relationships. While not a substitute for open communication, a polygraph can offer a starting point for rebuilding trust and understanding between partners. This is likely one of the most common reasons Kendall Investigations is asked to conduct polygraph examinations in Knoxville, Tennessee. In some cases, the results can be used to rebuild the relationship; in others, they may contribute to divorce proceedings and subsequent child custody battles. However, it isn't just romantic relationships that may need the help of a polygraph; they are also used to resolve all manner of family disputes.

7 - Forensic Psychophysiology Research

In the field of psychology, polygraphs are utilized for research purposes, particularly in studies related to deception, stress responses, and physiological indicators of emotional states. These studies contribute valuable insights into human behavior and inform the development of more effective interrogation techniques.

With its ability to measure physiological responses to stress and deception, the polygraph has found application in a range of fields beyond its original intent. While not without controversy and limitations, polygraphs can be a valuable tool in seeking the truth when used judiciously and in conjunction with other investigative techniques. As technology advances, new applications and refinements in polygraph technology will likely continue to emerge, further expanding its potential uses.

Uncover the truth!


Ken Shull served as a Special Agent with the FBI for almost 25 years and was head of the FBI Polygraph program until his retirement in 2001. At that time he set up the Kendall Investigations practice as a private investigator in Knoxville, TN offering Polygraph services, private investigations, and security guards. Ken is a member of the American Polygraph Association and The American Association of Police Polygraphists.

The Truth is Still the Truth Even if No One Believes it, A Lie is Still a Lie Even if Everyone Believes it.