Colorado television station KUSA 9News investigative reporter Jace Larson examines the use of the “Computer Voice Stress Analyzer” (CVSA) in the state:
KUSA – A device used by Colorado law enforcement agencies to identify when someone is lying, may not work and may be costing taxpayers money.
Computer Voice Stress Analyzers (CVSAs) claim to measure changes in a person’s voice that indicate a lie.
However, three recent studies say the device does not accurately tell the difference between a person lying and a person telling the truth.
CVSAs have been used by 21 law enforcement agencies in Colorado.
Studies by the National Academy of Sciences, the International Association of Chiefs of
Police and the Department of Defense question the validity of CVSAs.
In 2006 a University of Florida study found CVSAs, “performed at chance-level for deception, truth and stress.” The same study went on to say, “false positive rates were high.”
Westminster Police Investigator Wayne Read doesn’t agree though. He and members of his department have used the device and swear by it.
“I know how to operate the instrument. I know how the instrument works. I don’t think I could deceive the instrument,” said Read.
Read’s belief in CVSA despite the scientific evidence against it is reminiscent of the dogged belief of polygraph operators in their own pseudoscientific form of lie detection, despite broad consensus among scientists that it has no scientific basis.
Instructors who teach law enforcement agents how to read the test agree.
“It’s not audible to the human ear,” said Ben Conrique.
Conrique works for The National Institute for Truth Verification, the company selling CVSAs.
“Voice Stress indicated whether or not a person is telling the truth,” said Conrique.
And yet the National Institute for Truth Verification admitted before a federal court that CVSA “is not capable of lie detection.”
The National Institute for Truth Verification sells each device for about $10,000.
Agencies in Colorado have spent more than $331,000 on training and equipment.
“You only spend that type of money on something that has a proven success rate,” said Conrique.
However, experts who oppose CVSAs believe the devices do not work and that they lead to false confessions by suspects.
Deputies in Maricopa County, Ariz. suspected Robert Louis Armstrong of triple murder.
They questioned him for 10 hours in 2003. After deputies told him his test showed he was lying, Armstrong confessed.
Evidence emerged later proving Armstrong was out of the state at the time of the murders and he was freed.
He sued the sheriff’s office.
9Wants to Know tried to speak with deputies in Maricopa County but they declined.
Several agencies around the county have decided to stop using the CVSAs and now rely on other methods such as a polygraph test.
Unfortunately, polygraph tests, too, are completely unreliable as a means of lie detection. They are inherently biased against the truthful, yet easily manipulated through the use of simple countermeasures. See The Lie Behind the Lie Detector for a thorough debunking.
“If you think the CVSA is going to tell you whether witnesses or suspects are telling the truth, you’re gravely mistaken,” said CVSA opponent Richard Leo.
Leo is a criminologist and professor of law at the University of San Francisco.
Leo told 9NEWS if a law enforcement agency buys this device, “You’re wasting your money and you’re wasting public money.”
“You might as well be flipping coins or reading tea leaves or reading an Ouija board,” he continued.
The following are agencies that have confirmed to 9Wants to Know that they own or have used CVSAs:
*Boulder Police Department
*Brighton Police Department
*Broomfield Police Department
*Colorado Division of Wildlife
*Douglas County Sheriff’s Office
*El Paso County Sheriff’s Office
*Englewood Police Department
*Federal Heights Police Department
*Fort Morgan Police Department
*Glenwood Springs Police Department
*Golden Police Department
*Grand Junction Police Department
*Lakewood Police Department
*Lamar Police Department
*Longmont Police Department
*Moffat County Sheriff’s Office
*Northglenn Police Department
*Sterling Police Department
*Thornton Police Department
*Westminster Police Department
*Yuma County Sheriff’s Office
For further reading and video links, see the KUSA 9News website’s feature page, The Truth About Lies. and for discussion, see the CVSA and other Voice Stress Analysis Applications forum of the AntiPolygraph.org message board.