By Liz Clarke

South Africa's billion-rand security and insurance industries, as well as police and investigative services, could be forced to rethink lie-detecting strategies following an international probe into the reliability of polygraph testing.

The polygraph, used extensively in South Africa to uncover criminal and fraudulent activities, was denounced this week by the National Academy of Science, the United States' premier scientific organisation, which slated it as "more art than science" and stated that "virtually no serious research" had ever been done on its efficacy.

Although polygraph equipment cannot detect a lie, it charts physical responses, including blood and breathing rates, via a monitoring system wired to various parts of the body. The answer to each question is rated according to the response.

The academy's findings, which are expected to outlaw polygraphing as an investigative tool in America, where it is routinely used by the CIA and the National Security Agency, will also have a spin-off effect on the multi-million-rand polygraph industry in South Africa.

'Its main advantage is in narrowing down the number of suspects'

Although the results of polygraph tests in South Africa are inadmissible in court, they are widely used by large corporations "in-house" to determine guilt or innocence of suspects, often leading to dismissal.

Jacques Marnewicke, head of forensic investigations for insurance giant Sanlam, said that for some time his organisation had realised that polygraph testing should be treated with caution.

"We have used it as an investigative tool in in-house fraud claims, but never as a primary source of identifying a suspect. I would say its main advantage is in narrowing down the number of suspects in a case."

The polygraphing division of the South African Police Services in Pretoria, however, says it will not be swayed by the American investigation. Media liaison officer Francois Becker said: "We find it an accurate and invaluable tool in our investigations and certainly have no intention of scrapping it."

Shaun Webster, head of Securico - one of KwaZulu-Natal's largest security companies, said: "I don't say it is the only tool we use, but in most cases, the polygraph test confirms our suspicions - but I do agree it must be used correctly."

'It is playing Russian roulette with people's lives and careers'

In a landmark case in South Africa a leading polygrapher, Malcolm Nothling, has agreed to testify as an expert witness in a disciplinary hearing involving a doctor found guilty of inappropriate behaviour, an accusation supposedly "confirmed" by a lie detector test.

Although his testimony could ruin his career, Nothling said that he could no longer live with the "reality" that polygraph testing was "a profoundly flawed" procedure.

"It doesn't surprise me that a report of this nature has been done. Although I have no scientific evidence, I have suspected for some time that the results of polygraph tests are not always accurate. In fact, I would go as far as to say they are biased more against the truthful person than they are against those who are lying."

Nothling said that the day he beat the test by using "certain techniques" available over the Internet was the day he realised it was no longer a reliable-enough tool to establish innocence or guilt. "I think it is playing Russian roulette with people's lives and careers," he said. "We all want a crime-free society, but not when criminals are getting away with their activities and the innocent are possibly being victimised."

Published on the Web by IOL on 2002-10-12 20:04:01