Q&A: Don’t use lie detectors to investigate theft

Question: Our petty cash has been disappearing lately. There are three employees with access to the cash drawer. Can we use lie detectors as long as we test all three?
 
Answer: No, that’s not enough to justify such a test. Although you’re attempting to be non-discriminatory in testing everyone, using lie detectors on employees is usually illegal. The Employee Polygraph Protection Act (EPPA) prohibits employers from running lie detector tests on applicants or employees, asking about lie detector test results, or taking adverse action against an applicant or employee who refuses to take a test. There are a few limited exceptions for private employers that involve polygraph tests only. (Polygraphs are a specific type of lie detector, using an instrument to record physiological indicators in response to questions.) One exemption applies if you reasonably suspect one of your employees of being involved in a workplace incident that results in economic loss and the employee had access to the property that is the subject of your investigation. Before giving the test, you must give the employee notice and the basis for your suspicion. The need to have and communicate your reasonable suspicion is emphasized by a recent penalty assessed against an Arizona-based medical clinic. The clinic required five employees to undergo a polygraph test because of ongoing cash shortages. However, the clinic didn’t show why it had a reasonable suspicion, nor did it tell any of the employees why it suspected them. As a result, the clinic was assessed $15,000 in civil penalties (U.S. DOL news release, Aug. 2019).
 
Instead of using a machine to test for truth, conduct a good-faith investigation. Ask open-ended questions and collect objective evidence from all relevant employees. Your Vigilant employment attorney can help you develop legal questions for an investigation of this nature. For more detail about the EPPA and the limited exemptions, refer to the U.S. Department of Labor Fact Sheet #36.