What Questions Are Asked on a Police Polygraph? Unraveling the Mystery Behind the Lie Detector Test
The polygraph, often referred to as a "lie detector" test, is a controversial tool used by law enforcement. While its admissibility in court varies widely, it remains a common investigative technique. Understanding the types of questions asked during a police polygraph is crucial to comprehending its role in investigations. This isn't a definitive list, as the specific questions will vary greatly depending on the case, but it provides a framework for what to expect.
The process typically involves three main types of questions:
1. Irrelevant Questions: Establishing a Baseline
These are questions unrelated to the crime under investigation. Their purpose is to establish a baseline of the subject's physiological responses (heart rate, blood pressure, respiration, perspiration). Examples include:
- "Is your name John Doe?"
- "Were you born in 1980?"
- "Is today Tuesday?"
The examiner analyzes these responses to understand the subject's normal physiological reactions under non-stressful conditions. Any significant deviations from this baseline during the relevant questions become a key part of the interpretation.
2. Relevant Questions: Getting to the Heart of the Matter
These are the core questions directly related to the crime. They are carefully worded to focus on the specific actions and knowledge pertinent to the investigation. For example, in a theft case, relevant questions might include:
- "Did you steal the money from the office?"
- "Were you in the building at 2 a.m. on the night of the robbery?"
- "Do you know who stole the money from the office?"
- "Did you see anyone else steal the money from the office?"
The phrasing of these questions is critical. Ambiguity can lead to inaccurate results. The examiner often uses several variations of the same relevant question to gauge consistency in the responses.
3. Control Questions: Measuring Deception
These questions are designed to elicit a deceptive response even from an innocent individual. They are general questions about past behavior that most people would find embarrassing or incriminating to admit to. These questions aim to gauge the subject's response to deception. Examples include:
- "Have you ever lied to someone you cared about?"
- "Before the age of 21, did you ever do anything illegal?"
- "Have you ever stolen anything?"
The examiner compares the physiological responses to the control questions with the responses to the relevant questions. A stronger reaction to the relevant questions than the control questions might suggest deception, although this interpretation is far from foolproof.
What are the limitations of a polygraph test?
Polygraph tests are not completely reliable and are inadmissible in many courts. Their results depend heavily on the examiner's skill, the subject's physiological makeup, and even the subject's mental state. Factors like anxiety, medication, and even a prior experience with polygraphs can significantly impact the results.
Are the questions always straightforward?
No, questions can be nuanced and indirect. The examiner may use various techniques to elicit responses, including:
- Probing questions: Follow-up questions designed to clarify answers or delve deeper into specific points.
- Hypothetical questions: Exploring possible scenarios without directly accusing the subject.
- Multiple choice questions: Offering different options to test the subject's consistency.
Can I refuse a polygraph?
In most situations, you have the right to refuse a polygraph test. While refusing may be viewed negatively by investigators, it's not considered evidence of guilt in itself. Remember to consult with an attorney before agreeing to any polygraph examination.
In conclusion, the questions asked during a police polygraph are carefully constructed to assess truthfulness through a complex analysis of physiological responses. However, the test's limitations and lack of scientific consensus underscore its problematic nature as a definitive measure of guilt or innocence. Understanding the types of questions involved is crucial in interpreting the test’s often ambiguous results.
