VANCOUVER (CP) – Lie detector technology less costly than controversial polygraphs is catching on among smaller Canadian police forces, scaring some doctors who say it’s even less reliable.
The computerized voice stress analyser (CVSA), which purports to pick up tremors in the voice when a person is lying, “isn’t more than 50 per cent accurate,” said University of Toronto psychiatrist John Furedy.
“It is however, a very useful interrogation prop.”
The device was in the news this week for helping to cause another scandal within the Vancouver Police Department.
A Vancouver police officer who took a CVSA test in a job interview with another force admitted to lying under oath in a criminal trial, keeping goods that should have been turned in and withholding information about possible brutality by other officers.
To use this high-tech method of lie detection, the person being interviewed speaks into a microphone and software, run on a laptop, measures voice modulations.
The problem, Furedy said, is the operators of these machines don’t really know what they’re measuring.
“Voice can vary for a number of reasons and we don’t know whether it’s relative to certain stimuli or not,” he said.
The CVSA can be used on taped interviews and claims to give officers fresh leads on cold cases.
The $10,000 US device is used by more than 1,000 law enforcement and government agencies south of the border, and recently Canadian forces have been buying it, said a spokesman for its manufacturer, the National Institute for Truth Verification.
In the past two years departments in Lethbridge and Camrose, Alta., Edmunston and Rothsay, N.B., Vancouver and Saanich, B.C., in the Victoria area, have purchased the system from the West Palm Beach, Fla., company.
“Canada just recently started to really get involved,” said executive director David Hughes.
Hughes said the company only sells the CVSA to law enforcement and government agencies and has buyers sign a contract prohibiting them from passing the equipment on to anyone else.
There are fears that it could fall into the hands of organized criminals and be used on suspected undercover officers.
People taking the test don’t have to be hooked up to the machine, as is the case with a polygraph, and therefore wouldn’t know it was being performed on them unless told.
Marshall Chalmers, chief of the Camrose police force, said his investigators always inform people being tested because they have the right to refuse it.
“We say, OK, if you’re really telling the truth, prove it to us,” he said.
Chalmers said that in the first six months after purchasing the CVSA last August, it was used to solve 42 criminal cases.
“That’s a dramatic increase. It’s an integral part of our operation now.”
He said people have been brought in on charges and in the course of their CVSA test, other crimes they had committed came to light.
Before buying the device, Camrose police had to share a $20,000 polygraph machine with a number of municipal organizations. Only suspects of major crimes were eligible and there was a three-week wait list.
“That gave the suspects plenty of time to change their minds about taking the test,” Chalmers said.
The chief read about the CVSA in a police magazine and ordered one of his officers to research its effectiveness.
“This is leading edge technology and it is advancing quickly across the U.S.,” Chalmers said.
“We talked to numerous departments that are using it and were convinced of its accuracy. The CVSA is 100 per cent accurate. With the polygraph, there’s a grey area.”
Furedy said “it’s pretty scary” that police have that kind of faith in the machine.
“It’s a sign of a fundamentally superstitious society, certainly here in North America. The reality is that you can never determine with 100 per cent accuracy whether someone is telling the truth.”
Lie-detection devices are a scare tactic he said, that can sometimes push people into confessing to crimes they didn’t commit.
He has testified at many criminal trials and convinced juries to throw out such admissions.
One was the trial of a 74-year old crossing guard who was accused of molesting a girl. He was under accusation for a month and his community was suspicious of him, Furedy said.
He failed the test and in a post-exam interview that lasted several hours Furedy said the man got so angry he confessed in order to put an end to the questions.
“He just wanted to get out of there and figured he would talk to his lawyer and sort it out.”
The confession was eventually thrown out and the man was found not guilty.
Furedy said all lie-detection tests are subjective and results vary depending on the way the questions are worded and the relationship the interviewer has with the interviewee.
Saanich Police Insp. John Charlton, who heads the department’s detective division, said he only uses the CVSA to point him in the right direction.
“Every result we’ve gotten through the CVSA we then go out and corroborate with evidence and we’ve found it to be very effective. If there were any credibility issues with the device, we wouldn’t use it.”