Truth sought with, and about, voice test Device checks speech for signs of lying, but method has critics


From the beginning, Baltimore homicide detectives had doubts about Richard Allen Nicolas' story of an unidentified man firing a bullet into his car and killing his 2-year-old daughter, Aja. One clue was that his muffler was cold, indicating the car had been parked near a Northeast industrial park a lot longer than he said it had.

But it was not until a computer voice stress analyzer -- a device purported to detect whether a person is telling the truth by measuring tiny speech tremors -- indicated Nicolas was lying that detectives focused on him.

"We had the suspicion, but with the test, we had more conclusiveness," said Detective Raynard Jones. "Then we had to go out and put everything together."

Last year, after being presented with evidence police developed, a Circuit Court jury found Nicolas guilty of first-degree murder. He is serving life in prison without parole.

Similar cases are making believers in computer voice stress analyzers among a growing number of police agencies around the country. The machines, relatively cheap and simple to use, are supplementing and, in some cases supplanting, the more well-established polygraph as a lie-detection device in investigations.

But with its increased use, controversy over computer voice stress analyzers is growing, with critics complaining that the evidence supporting them is anecdotal, not scientific.

Legal challenges have been raised. A man who had sexual assault charges thrown out of court in Nevada has sued police and the analyzer's manufacturer in Florida.

Baltimore's police union challenged the device's use in an internal affairs investigation.

Many point to scientific studies conducted in the mid-1990s by the U.S. Department of Defense Polygraph Institute, which trains all federal polygraphers and researches technologies for detecting deception at Fort McClellan, Ala. The institute's conclusion: "We have found no credible evidence that voice stress analysis is an effective investigative tool for determining deception."

Several states, including Texas and Virginia, ban the independent use of voice stress analyzers.

"There's nothing on [the computer voice stress analyzer] to prove it works," said Frank DiTucci, executive director of the Texas Polygraph Examiners Board.

'Does not have validity'

Lie-detector operators are also stepping up criticism.

"It's convenient. It's cheap. But it does not have validity," said Donald A. Weinstein, president of the American Polygraph Association.

L Some members of the criminal defense bar also are concerned.

"That's why the thing becomes pernicious -- it can be used so easily," said Domenic R. Iamele, president of the Maryland Criminal Defense Attorneys Association. "Even if a suspect doesn't confess, he can destroy his defense."

Other defense lawyers are less critical of voice stress analyzers, provided the results continue to be inadmissible in court.

"As long as it is used as a law enforcement technique and not a prosecution technique, I have no problem with it," said Howard L. Cardin, one of Nicolas' lawyers.

Arguments over their merits aside, the polygraph and the computer voice stress analyzer operate on the same principle: that subtle physiological changes in the body are triggered by the stress of deception.

Developed in the 1920s, the polygraph measures several of these physiological changes, including heart rate, breathing and perspiration.

In the early 1970s, a device was developed to measure inaudible changes in voice vibrations caused by stress. The computer voice stress analyzer -- about the size of a laptop computer and sold by the National Institute for Truth Verification in West Palm Beach, Fla. -- is a modern-day version of that machine. Its $7,500 cost is less than half that of a polygraph machine, and it takes only a week of training compared with two to three months for a polygraph.

Some proponents of polygraphs acknowledge that the voice stress analyzer theoretically has several advantages, chief among them that the subject wears a clip-on microphone.

Criticism of voice stress analyzers hasn't halted growth in their use.

In the past three years, the number of law enforcement agencies nationwide using the device has doubled to about 600, said David A. Hughes, executive director of the company that makes the machines. "Police departments are finding out voice stress works. They don't need a study," he said.

In the 3 1/2 years since the Baltimore Police Department got its first machine, nine Maryland agencies have bought computer voice stress analyzers, Hughes said. Among them: Baltimore County and Montgomery County police and the Harford and Washington county sheriff's departments. State police are reviewing whether to use them.

To agencies that have used voice stress tests in hundreds of cases, whether the analyzer is as reliable as the polygraph is academic -- and irrelevant.

"I have confidence in both," said Maj. Allan Webster, head of Baltimore County's criminal investigation division, which got a computer voice stress analyzer last year, but occasionally uses polygraphs.

Webster said the voice stress analyzer has been "instrumental in us obtaining confessions, or at least finding holes in some stories."

Cpl. Dave Elliott, a Harford County sheriff's detective, said he used the voice stress analyzer to get a confession last year in the bludgeoning death of John Furches -- unsolved since 1995.

Elliott, based on an informant's tip, got one of several suspects to take a voice stress test. The suspect, Ronald A. Clayton, said he hadn't killed Furches, but when confronted with the machine's finding that he was being deceptive, Clayton confessed. "He said, 'You're right. I killed him. Thank God, it's over,' " Elliott said.

Clayton pleaded guilty to first-degree murder and is serving a 30-year prison sentence.

Not all Maryland police agencies are sold on voice stress machines.

Two decades ago, Ocean City police, unable to afford a polygraph, used an older, noncomputerized version of the analyzer. Today, the department uses only polygraph tests for stress.

"The reason we got away from the voice stress analyzer was that it only measures one physiological aspect of stress," said Ocean City Police Chief David C. Massey, who gave voice stress tests in the 1970s.

Several departments that use voice stress machines in criminal investigations, where tests are voluntary, rely on the polygraph to screen job applicants, whose tests are mandatory.

Baltimore police plan to use voice stress tests to screen job applicants, but have yet to start.

The department's attempt to compel a police officer under internal investigation to take a voice stress test drew a legal challenge in January from the police union, which said the test was not among those specified in state law that police officers could be forced to take.

Although the case was rendered moot -- the excessive use of force allegation was determined to be unfounded, according to attorneys for the union and the department -- police union head Gary McLhinney said the issue is more than a narrow legal one. "I'm against us being ordered to submit to something that's unproven," he said.

The validity of voice stress also is at the center of a multimillion-dollar civil lawsuit against the city of Henderson, Nev., filed in April by a 32-year-old probation officer. The man, known in court papers as John Doe, was charged with being an accessory to rape after a voice stress test indicated he was being deceptive about a sexual attack on a woman -- a charge dismissed for lack of evidence.

In the lawsuit, the man charged that the city and police chief were negligent in using the test results of an "unreliable" device in deciding to proceed with criminal charges and obtain an arrest warrant.

'An investigator's tool'

Henderson's police chief, Tommy Burns, said it accurately picked up several inconsistencies in the man's story.

"It's an investigator's tool," he said. "It's not a scientific device but it's no Ouija board."

The man's lawyer, Ian Christopherson, said he was putting the device on trial as well as the people who authorized its use.

"I think destroying [the computer voice stress analyzer's] credibility is important," said Christopherson. "You have an extremely dangerous piece of equipment which makes life-and-death decisions, which is an Ouija board."

Baltimore-area investigators said they would like the controversies about the machine to be cleared up but won't wait for that to happen.

"This is how I feel about it," said Baltimore police Detective John T. Brown, who heads the department's polygraph and voice stress unit: "It works for me. So how do you explain that?"

Pub Date: 12/25/98

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