A career in law enforcement is highly sought after, leading to a competitive environment with a rigorous selection process. The hiring journey involves numerous steps designed to assess a candidate’s mental, physical, and moral aptitude for public service. Among these hurdles, the polygraph examination remains one of the most discussed elements applicants encounter during their background investigation. This assessment is standard practice for agencies seeking to ensure the integrity and trustworthiness of individuals entrusted with public authority.
Is the Polygraph Test Required for Police Applicants?
The requirement to undergo a polygraph test depends heavily on the specific jurisdiction and the hiring agency. Federal law enforcement agencies, such as the Federal Bureau of Investigation (FBI), and the vast majority of larger state, county, and municipal police departments utilize this examination as a mandatory step in their pre-employment screening process. While no single federal law universally mandates the test, it is a near-universal standard for entry into major organizations requiring a high degree of public trust.
Smaller municipal or rural departments may occasionally substitute the polygraph with a different assessment, such as a Computer Voice Stress Analyzer, or in rare cases, skip it entirely. However, for any applicant targeting a significant law enforcement position in the United States, the polygraph is an expected and required component of the background investigation.
The Purpose of Polygraph Screening in Law Enforcement
Law enforcement agencies employ polygraph screening to fulfill two primary objectives related to the applicant’s suitability for a position of authority. The first objective is to verify the truthfulness and completeness of the extensive background investigation questionnaire submitted by the candidate, confirming details about past drug use, criminal history, financial integrity, or undisclosed terminations.
The examination is primarily a tool used to prompt admissions or confirm facts during the background investigation phase, rather than a stand-alone proof of guilt or innocence. By monitoring physiological responses, the test encourages applicants to be fully transparent about past indiscretions. This process allows the agency to assess the applicant’s overall integrity and moral character.
What to Expect During the Polygraph Examination
The polygraph session is conducted in a controlled environment, typically lasting between two and four hours. Specialized equipment monitors the body’s autonomic responses, with sensors attached to the applicant to measure several physiological indicators while questions are asked. This equipment includes pneumographs to record respiratory rate, a blood pressure cuff to monitor cardiovascular activity, and electrodes on the fingertips to measure electrodermal activity (skin conductivity). These indicators are tracked continuously, and the results are recorded in graphic form.
The procedure is generally divided into three main phases:
Pre-Test Interview
The examiner establishes rapport, explains the process, and reviews the questions that will be asked. This phase is crucial for establishing a baseline response.
In-Test Phase
Also known as chart collection, the examiner asks a series of questions. These often include both control questions and relevant questions related to the background investigation.
Post-Test Interview
The examiner discusses the recorded physiological reactions and seeks clarification or admissions regarding any potentially deceptive responses. The examiner relies on both the physiological data and behavioral analysis training to render a conclusion about the applicant’s truthfulness.
The Legal Status and Validity Debate
The polygraph remains a subject of considerable debate regarding its scientific validity as a tool for detecting deception. Many scientific bodies express skepticism, noting that nervousness or anxiety can trigger the same physiological responses interpreted as deception, potentially leading to high false-positive rates. Proponents, such as the American Polygraph Association, assert that when administered correctly, the test provides valuable data, with accuracy rates for screening applications ranging from 77 to 93 percent.
A significant distinction exists between the test’s use in criminal courts and its role in pre-employment screening. Polygraph results are generally inadmissible as evidence in criminal proceedings due to reliability concerns, but this restriction does not apply to employment screening.
The federal Employee Polygraph Protection Act (EPPA) of 1988 bans most private-sector employers from using polygraphs for pre-employment screening. However, the EPPA explicitly grants an exemption for government employers, allowing federal, state, and local law enforcement agencies to mandate the test as a condition of employment.
What Happens if You Do Not Pass the Polygraph?
A determination that an applicant was deceptive during the polygraph examination typically results in immediate disqualification from the current hiring process. The agency views an adverse polygraph finding as a failure of integrity, leading to elimination from that specific application cycle.
Applicants are often permitted to reapply to the same department, but only after a mandatory waiting period, which can range from six months to two years. An applicant who fails the polygraph with one department may still apply to a different agency, but the previous failure must be recorded and disclosed in future applications.
Experts advise that the best strategy is to be completely honest about minor past indiscretions during the polygraph and background investigation phases. An applicant who voluntarily discloses past mistakes, such as minor drug use or a youthful misdemeanor, is viewed more favorably than one who conceals information and is subsequently deemed deceptive.
The Full Scope of the Law Enforcement Screening Process
The polygraph examination is only one part of a multi-stage assessment designed to holistically evaluate an applicant’s suitability for police work. Before reaching the polygraph, candidates usually complete a written examination and a physical fitness test (PFT) to demonstrate cognitive ability and physical readiness. The PFT assesses components like running, push-ups, and sit-ups, ensuring the applicant can handle the physical demands of the job.
Following the polygraph, the process continues with a comprehensive background investigation, including checking employment history, interviewing references, and conducting credit and records checks. A psychological evaluation is mandatory, often including written personality inventories and a clinical interview. Finally, a medical examination is required to ensure the candidate meets the necessary physical health standards.