Bill Bishop of the Eugene, Oregon Register-Guard reports. Excerpt:
The mysterious murder of Cottage Grove resident Anita Cantu Lemmon in March brought sheriff’s investigators to their usual starting point: the next of kin.
But this time they had a new investigative tool, a Computer Voice Stress Analyzer, or CVSA.
Touted as the next generation lie detector, the device measures inaudible changes in the frequency of a person’s voice caused by the body’s involuntary response to stress. Theoretically, people can’t hide a big lie.
The Lane County sheriff’s office is among agencies using software that analyzes the voice patterns of suspects for signs of deception.
“It cleared the husband right away,” he said.
But, like the polygraph before it, the new technology is a magnet for criticism.
Criminal defense lawyers caution against its possible misuse to prosecute the innocent.
Polygraph experts, and government agencies that are heavily invested in the older technology, churn out studies to discredit voice stress analysis.
The National Academy of Sciences lambasted the entire truth-finding industry in a 2001 report. So many studies are so heavily influenced by vested interests, the academy charged, that their unreliability threatens the credibility of the entire body of research literature on the topic of lie detection.
David Hughes, executive director of the National Institute for Truth Verification, said the “polygraph mafia” is out to kill the voice stress analysis industry because they know it works, is easier to use than a polygraph and is less expensive.
Hughes’ institute manufactures the CVSA equipment used by the Lane County sheriff’s office, Eugene police, about 1,400 other police agencies and the military. CVSA software is installed in a laptop computer. The person interviewed speaks into a microphone whose signal is converted into charts depicting voice frequencies. Trained examiners read the charts to detect deception.
A tool that works
The concept emerged in the 1970s and has evolved with improved technology. Neither polygraph testing nor voice stress analysis may be admitted as evidence in court because of unreliability. However, both may be used by investigators developing cases.
“This is a tool. We state as strongly as we can that this alone should never be used to make an investigative decision,” Hughes said.
Training and proper analysis of the voice charts are critical to accuracy, he said.
“The most important thing we teach people is how to couch the questions,” Hughes said. “The difference is night and day.”
Criminal defense lawyers agree on that point, and often advise clients to decline to give an interview under voice stress analysis.
“It’s another Ouija board that police will use to dupe people into believing the technology is foolproof, which, in truth, it isn’t – and the police know it. It’s just another way to get some hapless individual to spill the beans on himself,” said John Henry Hingson III, an Oregon City lawyer and past president of the National Association of Criminal Defense Lawyers.
The big danger comes when police rely on the machine to reinforce a misguided theory about a case, to “search for the truth as they see it,” Hingson said.
“When it happens, it’s not malicious. The police think they’re doing the right thing,” he said. “The problem is sometimes they are wrong.”
Eugene defense lawyer Shaun McCrea said that very thing happened to a client she had a few years ago in Josephine County. An officer using a polygraph machine elicited a “confession” from the client, an elderly man with a hearing problem.
McCrea, a past president of the Oregon Criminal Defense Lawyers Association, said she vigorously investigated the case and the charges against her client eventually were dismissed without prosecution.
“The people using it want to believe it. If it says the person is stressed, that is going to convince the cops the person is guilty. The alternative hypothesis goes out the window,” McCrea said.
A shout line in this article characterizes the Computer Voice Stress Analyzer (CVSA) as “A tool that works.” But the “National Institute of Truth Verification,” which markets CVSA, has conceded in court that it “is not capable of lie detection.”