What Questions Are Asked on a Police Polygraph Test? Understanding the Process and the Questions
Polygraph tests, often used in police investigations, are a controversial tool. While not admissible as evidence in many courts, they can still significantly influence an investigation. Understanding the types of questions asked is crucial to understanding the process and its limitations. This isn't a guide to "beating" a polygraph (which is unreliable and unethical), but rather an informative overview of what to expect.
The Structure of a Polygraph Examination:
A typical police polygraph examination doesn't simply consist of a random series of questions. It's a structured process, usually involving three types of questions:
1. Irrelevant Questions:
These questions are designed to establish a baseline of your physiological responses. They're unrelated to the crime under investigation and serve as a control. Examples include:
- "Is your name [Your Name]?"
- "Is today Tuesday?"
- "Are you sitting in a chair?"
The examiner analyzes your heart rate, breathing, perspiration, and blood pressure in response to these neutral questions to determine your normal physiological state.
2. Relevant Questions:
These are the core questions directly related to the crime. They aim to elicit a deceptive response if you're involved. Examples could include:
- "Did you kill [Victim's Name]?" (Direct question)
- "Were you in the vicinity of [Location of Crime] on [Date of Crime]?" (Circumstantial question)
- "Did you handle the murder weapon?" (Specific detail question)
- "Do you know who killed [Victim's Name]?" (Knowledge question)
The phrasing of these questions is critical, and examiners often use several variations to get a clearer picture.
3. Control Questions:
These questions are designed to provoke a deceptive response even from someone who is innocent. They are about past misdeeds, focusing on behaviors most people would find embarrassing or uncomfortable to admit. Examples include:
- "Before the age of 25, did you ever do something you are ashamed of?"
- "Have you ever lied to deceive someone to get what you wanted?"
The examiner compares your responses to these questions with your responses to the relevant questions. The assumption is that someone guilty of the crime will show a greater physiological response to the relevant questions than to the control questions, while an innocent person might show a stronger response to the control questions due to the inherent guilt associated with admitting past misdeeds.
Important Considerations:
- False Positives and False Negatives: Polygraph tests are notoriously prone to both false positives (indicating guilt when the person is innocent) and false negatives (indicating innocence when the person is guilty). Many factors, including stress, anxiety, and even certain medical conditions, can influence the results.
- Lack of Scientific Validity: The scientific community largely rejects the validity of polygraph tests as reliable indicators of truthfulness.
- Ethical Concerns: The use of polygraph tests raises ethical questions, particularly regarding coercion and the potential for false confessions.
Conclusion:
While the specific questions asked will vary depending on the specifics of the crime, the overall structure remains consistent. Understanding this structure can help you approach a polygraph test with a clearer understanding of the process, although it's crucial to remember the inherent limitations and potential for inaccurate results. If you're ever subjected to a polygraph examination, it's advisable to seek legal counsel.
