You’re probably very familiar with polygraph tests, also known as
“lie detector tests.” After all, they’re depicted in
crime shows and in Hollywood all the time. A polygraph machine measures
blood pressure, heart rate, etc. in an attempt to correlate biological
changes with the telling of lies.
Historically, polygraphs were used heavily by the police when interrogating
suspects in criminal investigations, but their reliability has come under
question in recent years, thus they’re becoming less popular, in
part because courts across the country have been prohibiting their use
“Am I legally required to submit to a polygraph test?” No!
Nationwide, law enforcement cannot force people to take polygraph tests;
however, a lot of people don’t know that. Unfortunately, detectives
are in the habit of applying so much pressure on a suspect that refusing
to take a test can be treated like an automatic admission of guilt. If
the suspect refuses, it often leads to unwanted attention from detectives
who become convinced the suspect is hiding something.
Even when a suspect agrees to take a polygraph test and they pass it with
“flying colors,” the police can believe the suspect somehow
manipulated the test and found a way to beat it. So, there’s nothing
to gain by taking a polygraph, unless it’s done at the advice of
the suspect’s attorney.
Are Polygraphs Admissible as Evidence?
In California, polygraphs are not admissible as evidence unless the defense
and the prosecution agrees, even though each side may say something different
about the test’s accuracy. For example, a defense attorney may present
the results of a polygraph to persuade the prosecution to drop the charges.
Or, the defense may present the results to the jury (with the prosecution’s
approval), and let the jury draw their own conclusions.
We hope this information clears up any misunderstandings you had about
polygraph tests in criminal investigations. If you need
defense representation in Orange County,
contact the Law Offices of Virginia L. Landry, Inc. for a
free case evaluation.