What Questions Are Asked on a Polygraph Test for Police?
As a law enforcement agency, polygraph testing is a crucial tool in investigating and gathering evidence to solve crimes. The polygraph, also known as a lie detector test, is a machine that measures physiological reactions, such as heart rate, blood pressure, and breathing patterns, to detect deception. The questions asked during a polygraph test are designed to elicit truthful responses and identify inconsistencies in a subject’s account.
The Purpose of Polygraph Testing
The primary purpose of polygraph testing in police investigations is to:
• Confirm or refute information: The polygraph helps investigators confirm or refute the information provided by a witness, suspect, or accused individual.
• Gather accurate information: By detecting deception, the polygraph allows investigators to gather accurate information and build a stronger case.
• Identify inconsistencies: The polygraph helps identify inconsistencies in a subject’s story, which can indicate dishonesty or deception.
Types of Questions Asked
Polygraph tests for police typically consist of two types of questions:
Contents
Control Questions
Control questions are used to establish a baseline for the subject’s physiological responses. These questions are designed to be obvious lies, such as:
- "Have you ever been to the moon?"
- "Have you ever murdered someone?"
- "Are you a vampire?"
These questions help the examiner identify the subject’s normal physiological responses to lies, making it easier to detect deception during the remainder of the test.
Relevant Questions
Relevant questions are designed to elicit truthful responses related to the investigation. These questions focus on specific facts, events, or details related to the case, such as:
- "Did you see the suspect at the scene of the crime?"
- "Did you speak to the victim on the day of the incident?"
- "Were you present at the location where the evidence was found?"
These questions are tailored to the specific investigation and are intended to gather accurate information and detect deception.
Types of Relevant Questions
Relevant questions can be further categorized into three subtypes:
Stipulation Questions
Stipulation questions are designed to gather specific information, such as:
- "Did you have a phone conversation with the suspect on the night of the incident?"
- "Did you take the item from the location?"
Probe Questions
Probe questions are designed to uncover specific details or facts, such as:
- "What did the suspect say during the phone conversation?"
- "Who was present at the location when the item was taken?"
Comparison Questions
Comparison questions are designed to elicit information about specific details or events, such as:
- "Did you see the suspect’s vehicle at the scene of the crime?"
- "Did you notice anything unusual on the day of the incident?"
When to Administer a Polygraph Test
Polygraph tests can be administered at various stages of an investigation, including:
• Initial interview: Polygraph tests can be used to gather initial information and establish a rapport with the subject.
• Follow-up interviews: Polygraph tests can be used to follow up on previous statements and gather additional information.
• Challenging testimony: Polygraph tests can be used to challenge contradictory or suspicious testimony.
Conclusion
Polygraph testing is a valuable tool in police investigations, allowing investigators to gather accurate information, detect deception, and build stronger cases. By understanding the types of questions asked during a polygraph test, including control questions and relevant questions, investigators can effectively utilize this technology to solve crimes and bring perpetrators to justice.
Polygraph Question Examples
| Control Questions | Relevant Questions |
|---|---|
| Have you ever been to the moon? | Did you see the suspect at the scene of the crime? |
| Are you a vampire? | Did you speak to the victim on the day of the incident? |
| Did you murder someone? | Were you present at the location where the evidence was found? |
Takeaways
- Polygraph tests are designed to gather accurate information and detect deception in police investigations.
- Control questions are used to establish a baseline for the subject’s physiological responses.
- Relevant questions focus on specific facts, events, or details related to the investigation.
- Stipulation questions gather specific information, probe questions uncover specific details, and comparison questions elicit information about specific events.
By understanding the importance of polygraph testing in police investigations and the types of questions asked, investigators can effectively use this technology to solve crimes and bring perpetrators to justice.
