Polygraph examiners use polygraph equipment and techniques to determine whether individuals have answered questions truthfully or dishonestly. Polygraphs, often called “lie detectors,” are instruments that measure and record certain nonvoluntary body responses that are affected by the individual’s emotional state. To judge whether the subject has answered all the questions truthfully, the examiner compares the reactions recorded for questions that are not likely to cause stress with the reactions recorded for other questions. More than 2,500 polygraph examiners are members of the American Polygraph Association.
Polygraph Examiner Career History
Automatic body functions such as breathing and blood circulation are the basis for measuring individuals’ truthfulness. There is no one physiological response that reveals a lie. However, the rates of nonvoluntary processes change in response to stress, and stress is likely to increase when an individual is lying. One of the first attempts to use this knowledge to detect deception was made in 1898, when suspected criminals were interrogated while their pulse rates and blood volumes were monitored. Tests conducted in 1914 measured the volume of the air that test subjects breathed, and tests performed in 1917 showed that changes in blood pressure also could indicate whether the subjects were telling the truth.
John A. Larson, a medical student who worked with a local police department, invented the first modern lie detector in 1921. Larson’s instrument continuously recorded blood pressure, pulse rate, and respiration. His machine was called a polygraph, which means “many writings,” because it recorded all these processes simultaneously. Later polygraphs incorporated galvanic skin reflex testing, which recorded the changes in the electrical conductivity of the skin resulting from changes in perspiration levels.
Polygraphs have been used in police intelligence and security investigations since 1924. Lie detector testing has sparked a great deal of controversy. Many people object to such testing as an invasion of privacy and a violation of civil liberties. The validity of polygraph tests has often been questioned, and test results are generally inadmissible in court unless the defense, prosecution, and judge agree to their use. While studies have rated the validity of polygraph examinations at 80 to 98 percent, their reliability depends on the skill and experience of the examiner.
This controversy resulted in federal legislation. In 1988, the federal government established the Employee Polygraph Protection Act, which placed strict controls on the use of polygraph testing by private employers. Businesses are prohibited from requiring polygraph testing of employees or job applicants, except for employers engaged in security services, toxic waste disposal, or controlled substances, and employers under contract with the federal government. Polygraph testing is also permitted when an individual is suspected of committing a finance-related crime.
Polygraph Examiner Job Description
Although polygraph examiners often test suspects and witnesses in criminal cases, the applications of the polygraph are not limited to police work. For example the armed forces government agencies employ polygraph examiners to screen prospective civilian employees.
Before polygraph examiners meet the subject they will test, they gather information about the individual and the circumstances involved. They research the subject’s childhood, medical history—including use of medications, possible emotional illnesses, or drug/alcohol abuse—and inquire if the subject has a police record. In criminal cases, they may visit the police station, the crime scene, or the morgue for information.
After gathering this information, polygraph examiners spend at least an hour with the test subject to obtain information about background, current health, and knowledge of the circumstances that led to the polygraph examination. They try to calm the subject’s fears about the test by explaining how the polygraph instrument works and explaining the test procedure.
Next polygraph examiners develop test questions that are easy to understand and are not ambiguous. Before they administer the test, they read the questions to the subject to assure the subject that there will be no surprise questions. Then the examiners attach the apparatus to the individual to measure changes in certain nonvoluntary body responses.
The examiner fastens a tube around the subject’s chest to measure the rate of the subject’s respiration. A cuff similar to that found on a blood pressure meter is wrapped around the subject’s arm in order to record cardiovascular activity. Special sensors are placed on the subject’s skin to measure skin reflex. All these sensors are connected to the polygraph machine, which contains pens that respond to changes in the subject’s breathing, heart rate, and perspiration. An electric motor moves a roll of graph paper while the pens record the subject’s responses on the paper.
The actual testing session is rather brief; a 10-ques-tion test takes about four minutes. The test may consist of control questions, which are not likely to cause stress, and key questions, which are likely to produce a strong reaction if the subject is lying. Another form of the test includes a number of similar questions, with only one question containing the correct details. Because only the guilty subject knows which question has the right details, a reaction to that question can indicate their guilt or innocence.
Some people believe they can affect their reactions by taking drugs. But a drug that reduces an individual’s reactions to key questions also will reduce the individual’s reactions to the control questions. Thus the test results will still show a difference between the subject’s reactions when answering truthfully and when lying.
After administering the test, polygraph examiners evaluate the subject’s recorded responses and then discuss the results with the individual. If it appears that the subject has been untruthful, examiners try to give individuals a chance to explain the reasons for their reactions and may even retest them later.
In addition to administering and evaluating polygraph tests, polygraph examiners keep records and make reports on test results. They may appear in court as witnesses on matters dealing with polygraph examinations, and some also teach classes in polygraph operation and interrogation techniques.
Polygraph Examiner Career Requirements
You should take courses that help you understand how the body functions and how it is affected by stress. Courses in psychology, physiology, and biology will be especially useful. In general, take courses that will prepare you for college.
A college major in science or criminal justice will prepare you for this career. In addition, classes in English and writing will help prepare you to write reports, and classes in public speaking will help you develop the self-confidence you will need when testifying in court.
Candidates for lie-detection schools usually need four-year college degrees, but applicants with two years of college courses in criminal investigation plus five years of investigative experience may be accepted. Polygraph training in an approved school usually takes from six to eight weeks.
You must take polygraph tests upon entering a lie-detection school to ensure you have the good moral character this field requires. During your training, you learn how to operate the polygraph, how to develop and ask questions, how to interpret polygraph charts, the legal aspects of polygraph testing, and about the physical responses the polygraph measures. You observe polygraph tests administered by others, administer the tests yourself, and hear and see audiotapes and videotapes of your own performances. After you complete your study in lie-detection, you go on to an internship of at least six months before becoming fully qualified as a polygraph examiner.
Certification or licensing
National standards for training—as well as the polygraph equipment used—are established by the American Polygraph Association. The American Association of Police Polygraphists offers the certified forensic law enforcement polygraph examiner designation to its members who complete educational and experience requirements.
Although approximately 29 states license polygraph examiners, their requirements vary. Typical requirements include a high school diploma or the equivalent, either a bachelor’s degree or five years of experience as a detective, completion of polygraph training at a state-approved school, a six-month internship, and successful completion of a state-administered test.
Polygraph examiners must show good moral character and cannot have police records. You should speak and write well, have self-confidence, be alert, and be able to maintain objectivity and self-control. You also must be comfortable working with strangers and relate well to all kinds of people. It is crucial to show fairness; you should not be influenced by such factors as economic status, race, or sex.
In addition, you must be willing to work under pressure and under a variety of conditions and should not be shocked by distressing sights. You must understand the importance of protecting your subjects’ rights and maintaining confidentiality.
Exploring Polygraph Examiner Career
Because polygraph examiners must obtain cooperation from their test subjects, activities that offer contact with people can provide you valuable experience. Such activities include summer work as a camp counselor and volunteer or part-time work in a hospital or nursing home. Students at some colleges can volunteer for campus security patrols to develop their observation and investigative skills.
If you live near a largely populated area, you may be able to visit lie-detection schools and talk with staff members. You also may be able to visit courts and tour police facilities. Take advantage of any opportunities you get to talk with people who conduct police or private investigations.
Polygraph examiners are employed in many types of organizations, and their surroundings and the type of people they work with are determined by the nature of the organization. Many examiners are involved in law enforcement and may work for criminal or civil courts, police or sheriff departments, the FBI, or the Secret Service. Some work for the armed forces, and many others work for private businesses, such as retail stores, drug firms, companies that have their own security forces, and firms that provide testing services for other business organizations. The American Polygraph Association has more than 2,500 members.
Schools specializing in lie-detection often provide placement assistance for their graduates. Contacts made during internships can also provide job opportunities. Professional groups or periodicals that specialize in law enforcement and criminal justice often list job leads. In addition, qualified polygraph examiners can apply to courts and crime laboratories. Federal agencies have stricter requirements: You may need to take a civil service examination or have several years of investigative service before training in polygraph techniques.
In some cases people who are already involved in investigative work, such as police and private investigators, criminologists, and particularly military intelligence staff members, add to their skills by earning polygraph examiner certificates.
Polygraph examiners in civil service positions can advance through various job levels and eventually hold management jobs. Examiners who work for private security agencies can advance to such executive positions as director of operations. Polygraph examiners who are employed by business and industry in security positions may become supervisors and eventually head their department. In addition, some experienced polygraph examiners start their own agencies or work as security consultants or security systems specialists.
Polygraph examiners beginning their internships may earn from $18,000 to $30,000 a year, and experienced examiners earn as much as $60,000 a year or more.
Salaries for polygraph examiners are comparable to other law enforcement investigators. According to the U.S. Department of Labor, median annual earnings of salaried private detectives and investigators were $32,650 in 2005, with a range from less than $19,230 to more than $61,520. Median annual earnings of detectives and criminal investigators were $55,790, with salaries ranging from less than $32,920 to more than $88,570. Examiners who are paid employees often receive such benefits as sick leave, paid vacations, medical and dental insurance, retirement plans, and bonuses.
Most polygraph examiners work 40-hour weeks, although some work longer and irregular hours, including nights and weekends. Examiners usually work indoors, but may travel to their appointments, often carrying their polygraph equipment, which can weigh 25 pounds or more.
Polygraph Examiner Career Outlook
Because of the 1988 Employee Polygraph Protection Act restricting the use of polygraph testing, there are fewer positions for private polygraph examiners than there were before the act was passed. However, there is increasing need for law enforcement examiners, especially in the federal government.
The growing population and increasing crime rate may create more openings for polygraph examiners in the future. Courts in at least 30 states allow the use of polygraph test results as evidence, and public pressure for reducing court backlogs may increase the use of polygraph tests.