When shoould You Turn to Polygraph Examination

How much do you know about polygraph testing? The answer depends on your own personal background. If you are a member of law enforcement or work in the legal profession, then you have likely come across a polygraph exam more than once in relation to a case. If you work in a corporate or government setting, you may have had to take one as a condition of your employment. However, if you are the average person, you have probably only seen them on TV or in the movies! You might not realize that the application of polygraph examination in Knoxville is incredibly diverse. Let’s talk about some of the different situations when you might need a polygraph examination in Knoxville.

What is a Polygraph?

Let’s start by summarizing what a polygraph examination actually entails. The subject is hooked up to a polygraph machine that measures physiological responses in the body, including respiration rate, blood pressure, heart rate, and skin conductivity. By monitoring changes while answering questions, the examiner can determine whether the subject is lying.

Criminal & Civil Cases

In both civil and criminal lawsuits, presenting appropriate evidence is essential. If there is not enough evidence, a polygraph examination in Knoxville can help to bolster the evidence or prove the credibility of a witness. Police will also use polygraph examinations during their investigations. It is important to note that legally you cannot be forced into taking a polygraph examination in Knoxville, and refusal to do so is not allowed to impact the outcome of your case. However, if you are trying to prove your innocence, your attorney may encourage you to take a polygraph to support your case.

Pre-Employment Screening

Polygraphs can be used as part of the pre-screening process for employment, but only under very specific circumstances. Government agencies will often use polygraph examinations in Knoxville when hiring individuals for sensitive roles. Most private employers are not allowed to require a polygraph test for pre-screening or at any point during employment, as per the Employee Polygraph Protection Act (EPPA). The EPPA does permit polygraph tests as pre-employment screening for specific industries, including security service firms, armored car services, pharmaceutical manufacturers, distributors & dispensers, and government agencies. However, these must still be conducted under strict guidelines. The act also permits the use of polygraph testing during investigations in private firms where an employee is suspected of theft, embezzlement, or other activities that result in an economic loss for the employer. Again, this must be conducted according to the guidance set out by the EPPA. One of the most important factors is that your polygraph examiner must be licensed and bonded with professional liability insurance.

Monitoring Sex Offenders

Many federal districts require registered sex offenders to submit to a polygraph examination at regular intervals as part of their treatment or rehabilitation program. The most common frequency is every six months. This can help expose any parole violations and also acts as a deterrent since the offender knows they are being closely monitored.

Homeland Security

Polygraph is also used for issues relating to homeland security. Federal bodies that are responsible for our country’s safety, such as the CIA, FBI, and NSA, will routinely use polygraphs when investigating crimes or threats to our nation’s security. Here’s a fun fact - Kendall Investigations founder Kendall W. Shull is a former FBI special agent and was in charge of the FBI’s entire Polygraph Program in Washington, DC. If you need a polygraph examination in Knoxville, nobody is more qualified to take care of your polygraph needs!

Relationship or Family Struggles

One of the most common reasons for a polygraph examination in Knoxville is to prove or disprove infidelity! At Kendall Investigations, we see many couples trying to repair their relationship following accusations or evidence of infidelity. If one party suspects their partner and they deny any wrongdoing, a polygraph can give some closure by revealing the truth once and for all. Even if the cheating partner has admitted their guilt, many couples find a polygraph is the best way to wipe the slate clean as it can hello to ensure all of the affairs have been put on the table and new ones won’t come to light in the future. We work with various relationship counselors and therapists to administer polygraph examinations in Knoxville as part of their therapy program to get relationships back on track. Polygraphs can also help gather evidence for custody battles and divorce hearings. Families also use them to put family feuds to bed or clear their names in allegations of abuse. There are many ways that private individuals can benefit from a polygraph examination in Knoxville.

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.