A polygraph test measures indirect signs of lying by measuring a person’s blood pressure, heart rate and breathing patterns. The polygraph does not measure whether someone is telling the truth; it measures physiological responses that could indicate if a person is lying.
Criminal investigators and employers are two of the main groups who ask people to take lie detector tests.
If you are ever asked to take a lie detector test, you should consult with a Los Angeles criminal attorney before deciding whether or not to submit.
The results of a polygraph test (such as your blood pressure and pulse, or the operator’s interpretation) are not always admissible in court.
Their admission depends on where the case is filed (the state or federal district).
The states and the federal courts apply different legal standards when deciding whether a polygraph is admissible as evidence.
One of the key points to remember about lie detector tests is that they are used by law enforcement as a way to gather evidence against suspects.
All of this evidence that the state gathers—from the analysis of pre-test questions, to post-test interviews and even test results themselves—are used not only to determine whether you are guilty or innocent in a criminal case, but also as part of its investigation into your actions.
Even if a court refuses to allow the results of an alcohol or drug test as evidence in a trial, it can still be used by the prosecutor. The prosecutor may use this information to determine what charges should be filed against you and what defenses he might have available to challenge your case.