In Texas, people who are accused of sex crimes might be asked to take a polygraph test (lie detector test). Although some might view a polygraph test as a quick way to clear one’s name, the test itself is not 100 percent accurate, as explained by an article from How Stuff Works:
“When the polygraph test starts, the questioner asks three or four simple questions to establish the norms for the person’s signals. Then the real questions being tested by the polygraph are asked.
Both during and after the test, a polygraph examiner can look at the graphs and can see whether the vital signs changed significantly on any of the questions. In general, a significant change (such as a faster heart rate, higher blood pressure, increased perspiration) indicates that the person is lying.
When a well-trained examiner uses a polygraph, he or she can detect lying with high accuracy. However, because the examiner’s interpretation is subjective and because different people react differently to lying, a polygraph test is not perfect and can be fooled.”
Put simply, even an innocent person can “fail” a polygraph test, which can lead prosecutors and investigators to believe the person is guilty. On the flip side, even if one “passes” a polygraph test, the results are usually inadmissible in court. This means a defense attorney usually cannot use polygraph test results to persuade a judge or jury that you are innocent.
You have an absolute right to decline a police polygraph test. If police, Child Protective Services (CPS) or any government agency asks you to take a polygraph test, immediately contact an experienced Houston sex crimes attorney to go over whether you should take the polygraph test. At Scheiner Law Group, P.C., we routinely work with private polygraph examiners who can help determine whether you might pass a police or CPS polygraph if you ultimately elect to take a government test.
A sex crime accusation can cause serious damage to a person’s reputation and career. Defend your name and your rights. Exercise your Miranda Rights by seeking out the help of a trusted Houston sexual assault lawyer like Grant Scheiner or Jose Ceja, as soon as possible.
(Source: How does a lie detector (polygraph) work?; How Stuff Works)