Can an Employer Watch the Lie Detector Exam through a 2-Way Mirror?


Let’s run through a scenario. You’re a business owner running an operation where you sell gold and silver coins to the retail market. A few months ago, your logistics manager told you they were short a tube of ten gold American Eagles from your inventory stocktake assessment.

They inform you they’re confident it’s not a theft, just a misplacement of the coins between the sales department and your logistics team. After nearly three months of running recons, they can’t find the bullion.

No one in your company decided to hand in their resignation, and the team remains intact, but the coins are still missing. What do you do as a business owner? It’s clear to you there could be foul play underfoot, and someone in the sales or logistics department may have stolen the coins for some reason.

We’re talking about a serious theft here. That’s close to $20,000 in inventory that’s unrecoverable at this point. After consulting with your attorney, they recommend using a polygraph to interview the team and uncover the thief.


The Employee Polygraph Protection Act and How it Relates to Monitoring Polygraphs

Can you polygraph your employees? Is that legal? The last thing you need is for your employees to launch a lawsuit against you for unfair practices in the workplace. You’re already down twenty grand, and the thought of losing a couple hundred thousand through lawsuit settlements seems even more unsettling.

As a high-value company processing sales of gold and silver coins, you have the right to polygraph your team. Your attorney walks you through “The Employee Polygraph Protection Act” of 1988, explaining your rights as an employer when instituting a polygraph policy at your company.

The Employee Polygraph Protection Act of 1988, also known as the “EPPA,” clearly outlines employer and employee rights when working with lie detector tests. You see, the conflict around polygraphs started in the late seventies after a series of wrongful convictions from using this technology in the workplace stirred controversy in the industry.

As a result, the US government instituted the EPPA to protect employees from their employers’ wrongful use of polygraphs. Generally, employers may not use polygraph policies in their pre-employment screening process, nor can they use them to interview current employees.

However, there are loopholes in the EPPA specifying the lawful use of polygraph examinations in the workplace. If the scenario complies with the legislation, employers have the right to polygraph their employees if they follow the correct procedure.

In your case, your business handles high-value assets, and there’s a financial risk to your business if you can’t recover the missing coins. Your attorney recommends an approved polygraph company for handling the interviews.

After contacting the company, they insist you have the right to interview your staff. They also assure you they have all the required waivers and paperwork to carry out the polygraph policy legally.


Can Employers Use 2-Way Mirrors in Lie Detector Tests?

After notifying your team they’re undergoing polygraphs to clear them for possible theft, you notice changes in their behavior. Through your CCTV installation in the office, you see two of your sales team members talking with each other more than usual.

This behavior is suspicious to you, and you immediately feel your internal radar activated, suspecting them of the crime. However, you need solid proof to confirm your suspicions. The activity between the two suspects continues over the next two days, and you become more entrenched in your belief they’re the pair responsible for the alleged theft.

The polygraph company notifies you they’ll be conducting the exam at their facility, just a short drive from your office. You’ve seen polygraphs instituted before on TV shows and in movies, and you notice that in some of these instances, the detective monitoring the case watches the polygraph exam through a 2-way mirror.

As the company’s leader, you wonder if you can do the same. You feel that if you watch the two suspects during their polygraph interview through a 2-way mirror, you’ll catch onto their body language and potentially get the visual cues you need to confirm your suspicions.

Can you watch the interview through a 2-way mirror? Is that legal? You call your attorney to find out if it’s possible.


What are the Legal Issues Surrounding Employer Observation of Lie Detector Tests?

Your attorney notifies you that you have the right to watch the interview through the 2-way mirror. However, the interviewee must consent to you doing so. He informs you that the polygraph company will have a waiver for authorizing this process.

The attorney informs you that the employees have the right to refuse this request. The 2-way mirror brings another element of uncertainty into the polygraph process and may make employees uncomfortable during the exam.

A polygraph test is a serious situation. It’s an emotionally draining experience for the employees, who have the right to refuse your request. However, it won’t look good for them if they choose to decline your request to watch the interview. What are they trying to hide? Or are they just feeling nervous?


What are the Employee Privacy Rights when Taking a Polygraph?

Employees have a right to protect their privacy during a polygraph exam. The examiner asks them a series of questions, and they reply with yes or no answers. The questioning process involves the examiner asking sensitive questions relating to the employee’s behavior on the job and outside of work.

For instance, they might ask them if they have any outstanding debts they can’t service. Or they may enquire if they have a drug problem or have used illegal drugs in the past. Your employee might not want you to know about these behaviors because you might judge their answers in a negative light.

So, the employee has the right to refuse you access to monitoring the polygraph session. As an employer, you must comply with that request. You also can’t hold it against them if they make that decision. That means you can’t use this refusal as grounds for disciplinary action or dismissal.

However, the polygraph team informs you that you have the right to ask the employees if you can minor the session through a 2-way mirror. They begin to prepare the waiver for the employees. They notify them of your request and run through the questions they’ll ask the employees during their polygraph session.


The Impact of Observation on Polygraph Results

The polygraph examiner also notifies you of the possible outcomes of wanting to monitor the session. They tell you that your request might affect the exam’s result. A polygraph exam is an incredibly stressful experience.

During the process, the examinee’s (employee in this case) central nervous system is on high alert. When we experience stressful situations, it activates the autonomous nervous system to signal the sympathetic nervous system’s “fight-or-flight” response.

Fight-or-flight is the name given to the biological process involving the sympathetic nervous system preparing the body for action. In the past, this response would occur when stalked by predators.

The pupils dilate, allowing more light into the eyes to get a better view of your surroundings. The respiration rate increases, and the skin begins to sweat. These physiological reactions prepare us for dealing with a threat, such as a big cat stalking and attacking us for its next meal.

The same thing happens in a polygraph exam. The examiner’s equipment and software monitor these changes, assessing them as natural reactions or deceptive behavior. If the employee does show signs of deception when answering a specific question, the examiner presses the issue, repeating the question.

So, if you decide to monitor the session through a 2-way mirror, it introduces another stressor. The employee knows you’re watching them, and they might feel a heightened fight-or-flight response, causing them to fail the polygraph exam, even though they’re innocent.

You must decide if that’s what you want in the polygraph session. Does it really make a difference if you observe the session through a 2-way mirror? If the polygraph examiner manages to uncover employee deception without you there, it’s still the same outcome for the test as if you watched it. In fact, it might be more beneficial to the process if you didn’t watch it.

Your polygraph team notifies you of these issues before making your decision on whether to monitor the test or not.


Employer Best Practices for Conducting and Monitoring Polygraphs

As an employer, you have a right to polygraph your team in this case, and you have the right to monitor the session if you see fit. However, you have to follow best practices and legislation governing the process.

Even if the polygraph uncovers that the two salespeople you suspected of stealing did, in fact, take the coins, you can’t use these results to fire them. Polygraph results are not deemed definitive by the courts due to their history of inaccuracy.

While polygraph technology has come a long way in the last 30 years since the introduction of the EPPA, it’s still not allowed to use the results as a basis for dismissal. However, should they fail, it gives you more information about what happened to the coins.

You’ll know they stole them, but you have no legal right to take action. However, you can use this information to launch a legal law enforcement investigation into their suspected behavior. You decide to leave out the option of watching the interview through a two-way mirror in favor of getting a more accurate test result.

During the interview, the two suspected salespeople failed on the questions “have you ever stolen from an employer?” and “Did you steal the ten gold coins from the business?” There’s clear deception indicated through the test results, and the polygraph examiner notifies you of such in their pre-exam report.

Your attorney advises you to ask law enforcement to begin an investigation on the pair, and they do so. After investigating their financial records, a month later, the police uncovered that they had sold the ten gold coins to a precious metals broker in another county, just outside the city.

With your suspicions confirmed, you fire the employees and launch a criminal case against them under the advice of your attorney.


The Outcomes

There’s very little value to using a 2-way mirror in the polygraph process, but you have the right to request it. Provided you follow legal procedure and complete the processes required to monitor the session, there’s nothing the employees or their legal team can do to sue you for your actions.

That’s why employers must take legal advice before implementing a polygraph policy in the workplace. It’s also why it’s so important for you to work with a competent and experienced polygraph company.

With the right legal advice and procedures, you can polygraph employees and monitor the session without experiencing backlash from lawsuits launched against you by your employees. However, the polygraph is not a definitive means of identifying the suspected employees as thieves; it’s just a way to confirm your suspicions.

Watching the polygraph session through a two-way mirror doesn’t present much value to the process. While it may soothe your need to control the process, it may detract from its efficacy. In most cases, it’s best to leave it up to the examiner to make the judgment call on whether they identify deceptive behavior.

While this example of a theft in the workplace might not show the value of monitoring the polygraph session through a 2-way mirror, there may be instances where it’s valuable. For example, in cases involving crimes like sexual assault or murder, having detectives monitor the session through a 2-way mirror may add value to the process.

Detectives have specialized training in monitoring signs of deception in body language, and they might notice aspects of behavior in the suspect that the polygraph professional doesn’t identify.

Using a 2-way mirror for monitoring a polygraph session has its pros and cons, but whether or not it’s the right choice depends on the merits of the situation. It might not add value in cases like workplace theft and other business examples. However, it might give law enforcement an edge in bringing the suspect to justice in criminal cases.

Either way, the authority (business owner or law enforcement) and the polygraph examiner must comply with all legislation surrounding monitoring polygraph sessions. Failure to comply with the law may result in heavy lawsuits against the company, or law enforcement, by the examinee.