PAUL Woolley didn't see the knife until it was almost too late. The forensic psychophysiologist was analysing a lie-detector test when the woman opened her handbag, removed a blade and went for her husband.
"She was only little but she wasn't happy," Mr Woolley, founder of Australian Lie Detection Polygraph, said.
"When she found out her husband failed the test, she said, 'Sometimes you have to take matters into your own hands'. Out came the knife."
Mr Woolley, based in the Logan City suburb of Springwood, says infidelity makes people crazy.
The woman, one of thousands of Queensland clients who have paid for personal polygraph tests, had to be subdued.
Mr Woolley said the aggro occurred minutes after receptors were removed from her husband's fingers, chest and abdomen.
The highly sensitive instruments, attached to a laptop computer, checked the man's heart rate, nervous-system reactions and perspiration levels during an interview about an alleged affair. The man failed the test.
"Over the years, three clients have come in with weapons and you learn to expect the unexpected," Mr Woolley said.
On another occasion, an armed man arrived at Mr Woolley's house at 3am. The man, whose wife left him after he insisted she take a lie-detector test – which she passed – blamed Mr Woolley and wanted revenge.
"I asked him to leave and he became violent," the 39-year-old said.
For practitioners, it's the flipside of an otherwise lucrative industry. In the past two years Australian lie-detection agencies have experienced massive growth – good news for businesses that charge up to $1500 a test.
Industry insiders say the Sunshine State has become a gold mine for polygraph companies, private detectives and organisations selling everything from hidden cameras to GPS car trackers.
OzSpy stores, the brainchild of Brisbane entrepreneurs John Vlamis and Craig Mitchell, have set up six franchises between Townsville and the Gold Coast. Desktop hidden camera clocks and keyloggers – devices that monitor computer key strokes, emails sent and websites visited on home computers – are available in suburbia.
"It used to be people wanting cameras to catch staff stealing at work," Mr Vlamis said.
"But in the last 12 months it's swung around to husbands and wives, people trying to catch cheating partners."
Professional Detectives said Queenslanders were willing to spend up to $10,000 on partner-monitoring equipment such as hidden bedroom cameras and dollar-coin-sized bugs linked to portable radios.
"There's also GPS trackers that can be fitted under a car and used to monitor where the car goes, how fast it goes and how long it stops at any destination," Mr Rahim said.
"Others prefer to fit the family home with cameras and sound-recording equipment."
"Some people have the money and they just want to know. The warning signs are there and they want answers, so we provide the technology to make it possible.
"There's a way to test whether or not someone you love is lying to your face and there's a huge market for it."
Australian Psychological Society spokeswoman Heather Gridley said infidelity was at an all-time high. "Some people are chronically unfaithful and can't cope with the idea of putting all their eggs in one basket," she said.
Jane, 39, a Brisbane mother of three, agrees. She and husband William, from Carseldine on Brisbane's northside, have each had three polygraph tests at a total cost of $6000.
The troubled couple hired two interstate polygraph experts and flew them to Brisbane.
"I thought my husband had slept with my sister and he thought I'd slept with someone else," said Jane, 39.
"So we decided a lie-detector test was the only way to figure it out."
The first tests were conducted at the Brisbane domestic airport.
"I failed the first test and William passed," said Jane.
"But I wasn't happy with the way the tests were handled, so we contacted a different organisation and got a much better operator."
Four tests later, Jane was satisfied.
"My husband had slept with my sister, who later admitted it," Jane said.
"I slept with someone while we were separated . . . the tests helped resolve things."
Polygraph spokesman said all sorts of people signed up.
Age and lifestyle were not a barrier – but men were more likely to request a test.
"Men are more suspicious so we see more wives tested than husbands," "Men also fail more."
60 per cent of men and 20 per cent of women failed the tests.
"Men are more unfaithful," he said. "Women are certainly more intuitive. I believe in women's intuition. It's like a sixth sense."
A 19-year-old woman took a test to convince her 22-year-old fiance she was a virgin. She failed.
A woman in her forties wanted to know if her husband had cheated. He had, but not with a woman.
An 80-year-old man believed his wife cheated 40 years ago. She had. A DNA test later revealed one of the couple's three children had a different father.
Mr Woolley, who completed a psychology degree at Griffith University before studying polygraph science in the US, said: "It's all kinds of people from different socio-economic groups.
"The tests aren't cheap but people who really want them find a way to pay."
Rockhampton resident and mother-of-two Sally said her husband of 10 years took a test late last year.
The 31-year-old said he offered to take the test when she accused him of cheating.
"I'd been suspicious for so long . . . I tried to dismiss my fears but they were there and in the end I couldn't ignore them any more," Sally said. "It was making me sick. I was convinced he was being unfaithful, so when he offered I thought it could save us."
But Sally said her husband was shocked when she actually booked the test.
He failed and later admitted he was having an affair with a female co-worker. The couple split.
"It was hard at first, really hard, but I feel better now. Nothing could be worse than living with lies and slowly going insane."
Others who have passed the tests have walked away in disgust. "Some people can't get over the fact they were asked to take the test," .
"They feel disgusted their partner would ask them in the first place and it changes the relationship."
Industry insiders say the tests are between 96 per cent and 98 per cent accurate. The results, accepted in American courts and used as evidence in family and civil cases in Australia, are a collection of physical responses to questions.
A blood-pressure cuff is attached to the upper arm, a strap with sensors to the upper torso, a second strap to the upper abdomen. Blood pressure, pulse, respiration, perspiration and other physical responses are mapped while the subject is questioned. Signs of anxiety are linked to untruths. The higher the stress, the greater the likelihood the subject is lying.
"But the questions have to be specific,"
"Most people who come in want to ask everything from 'Has he cheated?' to 'Does he have hidden bank accounts?'
"But we have to ask something along the lines of 'have you had sexual intercourse with a woman other than your wife in the last 12 months?' "
Mr Rahim, who conducts polygraph tests in New South Wales and Victoria, said some questions could not be answered.
"I had a case recently with a couple in their 50s, both married for the second time, and they were fighting because the woman thought her husband looked at other women during their morning walk," Mr Rahim said.
"That would be almost impossible to prove and simply ridiculous. In some cases we just say No."
Mr Woolley said ,Others get answers. A Gold Coast woman, convinced her husband had sexually assaulted her while she was drunk, made him take the test.
The woman, who was intoxicated and blacked out, became suspicious when she woke with bruising to her upper thighs and buttocks. It turned out the husband, who said his wife fell out of a spa, was telling the truth.
A husband of 23 years failed when asked if he had slept with a man in the last 12 months. He later told his wife he frequented male prostitutes and regularly fantasised about men.
Relationships Australia spokeswoman Sherry Wright said it was a sad state of affairs.
"Anyone who tries to convince a partner they need a polygraph needs to realise the trust has already shattered somehow," she said.
"Statistics show us divorce rates have fallen in Queensland but it seems mistrust is very much alive and well."