Joseph Libowsky,
former Special Agent

In order to become a law enforcement officer, you must pass through a strict hiring process that includes several critical steps. All candidates are aware how important it is to prepare well for the written test and for the physical agility test, and realize the significant role of the background investigation. They all know that for most of the positions they will be required to undergo and pass a polygraph. However, they are not fully aware of what it means and that actually you can prepare for the test.

In the article below, you will find all the information you need about the polygraph test, what types of questions it includes and how to prepare for it, so that you don’t fail it while still telling the truth. It is crucial to keep in mind that this is simply a step of the process and that you are fully capable of taking it. There is no need to fear the polygraph test but rather perceive it as one more option to show that you are the best candidate for the position you are applying for.

polygraph test sample questions

Historical facts about the polygraph

The polygraph is also known as the lie detector and it is used to tell whether a person is telling the truth or not by measuring psychological indicators that include blood pressure, perspiration, pulse, skin conductivity. Ever since the first usage of the polygraph, there have been discussions on how reliable the results are. It is believed that there are people who can easily fool the machine and pass the test without any problem even when they are telling obvious lies.

Nevertheless, the polygraph is used to interrogate suspects and also by law enforcement agencies to screen their prospective employees.

It is interesting to note that the earlier forms of such a device were used in 1895. The device measured only blood pressure and was used in police cases. For the first time a device that recorded both the blood pressure and the breathing of the person was invented back in 1921 by John August Larson. It was actually used by the Berkeley Police Department.

William Moulton Marston invented a device that measured the blood pressure and used it for interrogating German prisoners of war. Even though his project was abandoned later, he is still referred to as the father of the polygraph. Find out how to Master the Polygraph

What is the police polygraph exam

The polygraph exam can be a breaking point in the process of applying to be a police officer. It is often part of the background check that is run on all candidates. The theory behind the test is that people get nervous when they lie. Hence, the device checks the involuntarily body responses of the candidates, while they answer the questions.

The polygraph is a machine that uses several sensors to detect changes in blood pressure, breathing, perspiration, etc. and a strip of moving paper that records the information. Nowadays, many polygraph examiners, however, use computer images instead of the analog tools.

The police polygraph exam is conducted by a polygraph examiner, who asks the questions, and is a technical operator of the device. They rely not only on the results of the machine but also on their experience to determine whether the candidate has told the truth or not to specific questions.

  Try a Simulated, Interactive Polygraph Exam


Why agencies use the polygraph

The overall aim of the polygraph test is to determine whether the information that you have provided and that the background investigation has revealed for you is correct. This will determine whether you are suitable to become a law enforcement officer or not.

Most of the agencies also believe that the polygraph can reveal certain information that cannot be obtained in any other way throughout the selection process. Besides, it is also one of the fastest processes to determine whether the information provided is actually true.

It is interesting to know that the polygraph test is used for candidates applying both for sworn and non-sworn positions in their departments, such as dispatchers or secretarial staff, and others working in a law enforcement agency who will have access to sensitive information.

Types of polygraph tests

In order for the polygraph test to take place, the candidate is attached to four or six sensors that will detect the changes in the different indicators. The test will then start with the so called pre-test interview that aims to collect some preliminary information to be used for the control questions. This is referred to as the Control Question Test, CQT. This is followed by the Directed Lie Test, DLT, where the examiner asks the candidate to deliberately lie a few times, so that your reaction can be recorded. Some of the questions may be of the “probable-lie” type, such as “Have you ever stolen anything?”. The idea is that we have all stolen a thing – a pen from work, a candy from our siblings – and that notion of a “theft” will make us a bit nervous and stressed while responding. The final type of test to be used is the Guilty Knowledge Test, GKT. In it, the polygraph compares the psychological responses to multiple-choice type of question concerning facts that you and the examiner know.

Of all the three types of polygraph tests, the GKT is considered to be the most accurate one. It is recommended as a good forensic tool, despite the controversy that goes with the debate how reliable the polygraph results are. Learn more about Sgt. Godoy’s Master the Polygraph

Sample questions from the polygraph test

During the polygraph test you will be asked mainly two types of questions. The first type are relevant ones about a specific accident – ” Did you provide classified information to the local newspaper yesterday?”. The second type are broader questions that are used as control questions – “Have you ever lied to someone who trusted you?”. It is expected that if you have nothing to hide, you will react more emotionally to the control question as you would start thinking whether you have really done something like that or not, while you would easily respond to the specific question. There will be also some questions, which are classified as irrelevant as well.

There are certain topics that will definitely be covered during your polygraph test for an entry level law enforcement position. According to the information provided by Police Test, there are 12 topics that will be covered by the examiner:

  1. Shoplifting or theft of money or merchandise from employer.
  2. Illegal drug trafficking or dealing.
  3. Illegal drug or medication use, including steroids.
  4. Use of alcohol.
  5. Falsification or minimization in your requested information.
  6. Participation in any type of organized crime.
  7. Arrests for anything other than minor traffic violations.
  8. Commission of a crime which has not been detected.
  9. Concealment of anything in your background that would affect your chances for this position.
  10. Involvement in a physical fight with another person, including domestic violence.
  11. Use of excessive physical force against another person.
  12. Payment or receipt of any bribes.

Keep in mind that giving a positive answer to any of the questions above means that you may be disqualified and cannot become a police officer. There are a few minor exceptions. For example, if you have shoplifted as a juvenile or for some agencies if you haven’t smoked marijuana in the last three years.

It is very important, however, to provide honest answers to all the questions. In your application, you have already provided answers to these topics and the fact that you are admitted to the polygraph test means that you have been doing well so far. Remaining calm and giving truthful answers will help you pass through this hurdle.

It is important to note that the polygraph test is not always 100% accurate and you may “falsely fail” the test. Below, you will find a few ideas how to be prepared for the polygraph and how to minimize the chances of failing.

  See a list of Polygraph Questions


Best advice how to perform well on the test

The best advice that you can get about passing the polygraph test is to tell the truth. The police department that is going to hire you does not demand that you have lead the perfect life so far but expects you to be an honest and truthful person who is going to perform the job showing integrity.

It is important to get a good night’s sleep and have a healthy breakfast, so that you can go to the test rested and relaxed. Dress well and put a smile on your face – you need to feel and look confident. Be nice to the polygraph examiner and the technician – they are not your enemies. Try to develop rapport and keep calm.

Keep in mind that your overall appearance and body language will also play a role in the final decision whether you pass the test or not. Therefore, you need to try and make a good first impression – try to be friendly and not to look nervous. Keep an eye contact with the examiner as avoidance of eye contact may be considered an attempt of deception. Learn, which are the body language signs that signal truth or deception.

Try to distinguish between the three type of questions that are used – irrelevant, relevant and control questions. Answer the questions honestly and to the best of your ability. Use short answers as Yes/No and avoid giving further clarification as this might be interpreted as if you are trying to hide something. It is also a bad idea to change the answer you have given so don’t do it.

If you follow these simple tips, you will be one step closer to passing the polygraph test successfully and eventually starting the job you have chosen.


How to prepare for the polygraph test

The polygraph test is often one of the most stressful exams for the prospective law enforcement officers. Therefore, it is a good idea to prepare for it in order to avoid to “falsely fail” it. As we already said, the polygraph measures mainly the levels of stress as an indication of whether the applicant is telling the truth or not and therefore you can fail it if you are too nervous even if you tell the truth.

In order to avoid that moment, it is a very good idea to prepare yourself using professional advice. Mastering the Polygraph is an online course developed by Sgt. Godoy that aims to help you pass the test by providing practical tips on how to do it. The course helps you to understand the process and teaches you how to practice some relaxation techniques while giving the answers. It has an in-depth tutorial with a simulated polygraph session that helps the learner prepare for the actual test. By getting the course, you can expect a mobile-friendly online course, that you can access without limits against a one-time fee. The best part of the course is that you get personal one-to-one support by Sgt. Godoy.

With the help of the course, you will be able to pass the polygraph test, since you will know what to expect and how to behave properly, so it is worth trying it.

As you can see, the polygraph test is part of the police hiring process that can be easily overcome with the right preparation for it. No matter if you would decide to take a preparation exam course or not, it is essential to keep calm and be honest and open while being tested. Now, that you know what you can expect during the actual polygraph test, you can cope with the stress and pass it with ease. Feeling confident in yourself is the key to turning your dream of becoming a law enforcement officer into reality. Start browsing the job openings and apply for the positions that you consider most attractive, knowing that you are ready to be tested.