A polygraph lie detector test is a type of evaluation that can be used during a criminal investigation or during an employment hiring process. A lie detector test uses sensors to evaluate the body’s responses to questions, including changes in heart rate or movement. The changes can allegedly indicate whether a person is being truthful or not.

The Federal Employee Polygraph Protection Act (EPPA) prohibits an employer from requiring employees or job applications to take polygraph tests. The types of businesses covered by this act include private sector employers with at least two employees which are engaged in interstate commerce activities and have an annual volume of business of at least $500,000.00. The act does not apply to public sector employers, which may include employers such as government and law enforcement.

California employees are protected by the EPPA as well as California Labor Code Section 432.2 among other laws. California Labor Code Section 432.2 mirrors the EPPA in prohibiting private employers from requiring an employee submit to a lie detector test. However, it also allows federal and public sector employers to require a lie detector test for employees.

It is important to remember that, in most cases, an individual is not required to submit to a lie detector test. Should an employer wish to administer such a test, either for an investigation or a potential employee, they should review local laws to make sure the employee’s privacy rights are not violated.

If an individual is asked by their employer or law enforcement to submit to a lie detector examination, it is advisable to consult with an attorney prior to agreeing to the test. An attorney can advise an individual on local laws regarding a polygraph and whether or not the employer is allowed to require one.

Are Lie Detector Tests Reliable?

In short, no. Lie detector test reliability has come into question in recent years. Lie detector tests measure and record physiological indicators during questioning. These include blood pressure, pulse, respiration and skin conductivity.

It was assumed that if an individual was telling a lie, their body would react by raising blood pressure, sweating and other physiological responses. However, these responses may also occur in the body when an individual is excited, anxious or scared. The polygraph test itself may cause nervousness and anxiety, which may be categorized as telling a lie when, in fact, the individual is being truthful.

Additionally, certain types of questions may elicit responses of anger or nervousness in an individual even if they answer truthfully. This may be the case if the question is very personal or embarrassing in some way.

What Is California’s Policy on Using Lie Detectors?

California has different rules for the private and public employment sectors regarding which employees would be required to take a lie detector test. A private California employer cannot require a current or prospective employee to take a lie detector test.

A California public employer, such as a government office, law enforcement or public safety employer may request an employee or prospective employee take a lie detector test. However, the employee or prospective employee may refuse to take the test. Retaliation against public safety officers who refuse to take the lie detector test is forbidden. The refusal cannot be noted in an investigation or used as evidence against the public safety officer.

What Is an Employer Required to Do Under California Law?

Under California law, an employer may request the employee or potential employee take a lie detector test. In order to get a lie detector test done, the employer must advise the employee or potential employee in writing that they are not required to take the lie detector test. The employee or potential employee must then consent to the test.

How Does California Law Differ from the EPPA?

There are subtle differences between California law and the EPPA on polygraph testing. The EPPA makes some exceptions and permits lie detector testing to current employees who are under investigation for theft at the workplace. California law, however, prohibits such a demand from a private employer.

Are There Alternate Methods for Eliciting Information from Employees?

Yes, there are alternate methods other than the lie detector test for eliciting information from employees. Since lie detector testing is often unavailable, or may be refused, employers may use other means of getting information from current or prospective employees. These methods may, however, subject an employer to liability. Examples of these methods include:

  • Using pre-employment investigators to conduct “security interviews;”
  • Psychological testing;
  • Pre-employment physical examinations; and/or
  • HIV testing.

There are reasons each of these methods may violate an employee or potential employee’s rights. Pre-employment investigations may result in an invasion of privacy. Psychological testing may violate disability discrimination laws. Pre-employment physical examinations should be done in limited circumstances and in compliance with the California Fair Employment and Housing Act and the Americans with Disabilities Act (ADA). In California, an employer may not condition employment on HIV testing. The results of a HIV test are to be kept confidential.

Can Law Enforcement Require an Individual to Take a Lie Detector Test?

No, law enforcement in the United States cannot require an individual to take a lie detector test. This is worth repeating. Law enforcement cannot require an individual to take a lie detector test in any state. Law enforcement can, however, attempt to convince an individual it is in their best interest.

An individual will often be told if they have nothing to hide, they should have no issue taking a lie detector test. This is not accuracy since, as discussed above, psychological indicators other than lying can cause the polygraph machine to indicate deception. If an individual is ever confused about their rights or feels overly pressured to take a test, they should request an attorney immediately.

Are Lie Detector Tests Admissible in Court?

Polygraph admissibility varies from state to state. Some states such as Arizona, California, Georgia, Nevada and Florida allow admission of polygraph evidence in criminal court if all parties agreed to their use.

Each state, however, places different emphasis on the accuracy of the test. For example, California allows attorneys to present test results to the jury and the jury draws their own conclusion. Georgia permits an individual to sue a polygraph examiner should a false result on the test cause them damages.

In many states polygraph evidence is inadmissible, no matter the circumstances. These states include Illinois, New York, Texas, Pennsylvania and the District of Columbia.

Federal courts have separate rules regarding admission of polygraph test results as evidence in court. The admission is generally at the judge’s discretion.

Why Are Lie Detector Tests Not Admissible in Court?

Lie detector tests are inadmissible in court because a scientific evaluation of the testing has shown they may be inaccurate. There are several factors that can lead to an inaccurate result, such as:

  • Defects or deficiencies with the machine itself or attached equipment;
  • Polygraph examiner bias; and/or
  • Inconsistent responses from the individual being questioned.

The stress of the polygraph exam itself may interfere with accurate readings. Nervousness may affect the way the individual responds to questions during the test.

When Should Someone Seek an Attorney’s Help?

As noted above, it is important to seek the advice of a California lawyer if you are asked to take a lie detector test. In an employment setting, a lawyer will assist you in determining if you are required to take the test. The attorney may also evaluate whether or not your rights were violated under California law or the EPPA. In a criminal setting, you are never required to take a polygraph examination and if you feel confused or uncomfortable, request an attorney immediately.

As an employer, consulting with a California lawyer will be an asset to your business. A lawyer can advise you how to set up hiring practices including a polygraph. A lawyer may also assist in setting up an employment process that does not violate federal or state privacy laws.