The Associated Press reports on Glynn County, Georgia’s use of and professed belief in “Computer Voice Stress Analysis” (CVSA). Excerpt:
BRUNSWICK, Ga. — Glynn County police have become true believers in a new sort of lie detector that analyzes stress in a suspect’s voice, but other police departments are not convinced.
The Computer Voice Stress Analyzer helped snare William David Tatro, who was convicted earlier this month for killing his wife and burying her in a garden in his front yard.
Tatro initially told police two different versions of what happened to his wife, Yukie Tatro.
Glynn police Sgt. Chip Anderson said Tatro first told them he “didn’t know where his wife was, that she (had) driven away in her car.” He then agreed to answer questions about her disappearance on the voice stress test.
“Mr. Tatro changed his story after we confronted him with results of his voice stress test, which showed that he had been deceptive in his statements about her disappearance. That’s when he told us that he killed her accidentally,” Anderson said.
Yukie Tatro’s decomposed body was found Oct. 5, 2000. William David Tatro is awaiting sentencing.
Jurors never heard any testimony about the voice stress test, but Anderson said it was “an important tool” leading investigators to Yukie Tatro’s body and her killer.
“It bolstered our feeling that (William Tatro) knew more about her disappearance than he was saying, and it showed us that we were going in the right direction with our investigation,” Anderson said.
About 1,200 law enforcement agencies nationwide use the voice stress test, including 38 in Georgia and 124 in Florida.
The instrument uses a special computer program to detect, measure and analyze the micro-frequency modulations in a person’s voice. The frequency changes can be used to determine lying or truthfulness, police said.
But neither voice stress analysis, nor the more traditional polygraph tests are admissible in court as evidence in Georgia, Florida or federal courts, authorities said.
Glynn County public defender Timothy Barton said the analyzer shouldn’t be used as evidence because, like a polygraph, it hasn’t been proved scientifically accurate.
“It’s a crude tool, but it’s a tool. I’ve got no problem with it as an investigative tool, as long as the police don’t use it to trick people,” Barton said. “We want the truth as much as the police do. If it helps get at the truth then I’m for it.”
While Glynn County public defender Timothy Barton has no problem with the use of CVSA as an “investigative tool, as long as the police don’t use it to trick people,” that is precisely how CVSA (like polygraphy) is used–as an interrogation tactic to trick suspects into believing that they have been caught in a lie, and to convince them that it is in their best interest to confess. Neither polygraphy nor CVSA has any scientific basis, and no reliance should be placed on the outcome of such “tests.”