She was a 23-year-old American college girl, smart, beautiful, funny and free-spirited and when she joined America's Peace Corps volunteers in the tiny kingdom of Tonga in 1976, Deborah Gardner had no shortage of admirers anxious to take her on dates.. Her reputation as the most beautiful girl in the Peace Corps had preceded her but Deb Gardner didn't want serious romance. She would happily go on dates, insisting on paying her way, but she was happy to stay single and fancy-free and most of the 70 male Peace Corps members in Tonga sadly accepted it, even though they thought it was a shame.
One man who didn't was Dennis Priven an introverted 24-year-old American who taught chemistry and maths at the country's leading Methodist high school. He had convinced himself he was madly in love with Deb Gardner and couldn't understand why she didn't feel the same.
Debbie, from a sophisticated Seattle background, had taken with gusto to the primitive Tonga life. She taught science and home economics at the posh Tonga High School but insisted on living in the country in a one-roomed hut.
She rode a bicycle, washed her clothes by stamping on them in a basin, never wore make-up, learned the local language and enjoyed native food. "My life," she liked to say, "is a wide-open adventure."
How could she have guessed that it was also tragically near its end?
Deb was always friendly to Dennis Priven — she was friendly to everyone — but he read far more into it than she had intended.
No one quite understood why Priven had joined the Peace Corps — he seemed to have little interest in the human race — never looked anyone in the eye and carried wicked-looking diving knife with him at all times.
He was also the best poker-player on the island and had won large sums from anyone unwise enough to play him. "He's absolutely ruthless at cards," said one victim.
A woman teacher who worked with Priven later explained: "The students are scared of him, not knowing that beneath that gruff exterior lies a tender heart of the sort that rescues damsels in distress.
"I keep wanting to match him up with some fluffy little wisp of a girl with a will of iron. They'd live happily ever after."
But the only girl Dennis Priven was interested in was Deb Gardner. One night he plucked up the courage to invite her to his house for dinner and she accepted. A friend helped him put the meal together but the dinner was a disaster.
Priven had bought his date an expensive gift which she felt unable to accept and the evening ended in unpleasantness and misunderstanding. Deb ran out of the house, got on her bicycle and rode home.
Later she told a friend: "He must have spent $100 on the dinner. Doesn't he know I don't want to go out with him?"
But he didn't and over the months Dennis Priven's infatuation with Deb Gardner became increasingly obsessive. She found it impossible to escape him: he visited her school every day on his bike, even after the vice-principal had told him that he was no longer welcome.
In part to escape him, Deb applied for a transfer to another island but before this could take place she attended a Peace Corps dance for a new group of volunteers. When Priven asked for a dance he was refused. This, it seemed was the final humiliation.
The following night he cycled cross the island to Deb's hut carrying a rucksack containing his knife, a syringe, a metal pipe and two jars of cyanide.
Later his friends would learn that he intended to knock his victim unconscious and then kill her with the cyanide but Deb was strong and fit and put up the fight of her life.
Stabbing at her with his knife, Priven gradually overpowered her, inflicting 22 vicious wounds before cycling off into the night leaving Deb bleeding and unconscious. Neighbours, woken by the noise, took Deb to hospital in an old truck but the damage to her aorta and carotid artery was so severe that she died shortly after admission. Priven had apparently planned to kill himself after the murder, but after making a few small cuts in his arms he changed his mind and cycled to a friend, who accompanied him to the local police station.
There Priven said: "I have tried to kill myself." He said nothing about the death of Deb Gardner. After his glasses and shoes were found in the victim's hut, Priven was arrested the following day and charged with murder.
He faced a possible death sentence and the Peace Corps threw in its resources to defend him, paying for expensive lawyers and psychiatrists to present the case that Priven had been insane when he killed Deb Gardner.
Washington insiders would later say that a directive had come direct from the White House instructing the Peace Corps to minimise the political damage that the case would cause — and to get Priven out of Tonga as quickly as possible. The prosecution complained in vain that it was unable to afford such expensive expert witnesses. A Crown solicitor told the court: "It appears to me that so far as the State Department is concerned all the consideration and pity is for Priven and none for the dead girl. I find this very strange justice."
It seemed to grow even stranger when after a nine-day trial the jury found Dennis Priven not guilty because of insanity after only 26 minutes. It was then arranged with the US State Department that Priven would return to America to receive hospital treatment until he was fit to return to society. But arriving in Washington, Dennis Priven refused to go to hospital — and Washington police said they had no power to arrest him.
Priven then suddenly disappeared, sparking off world headlines that he had been shot by a relative of the dead girl the moment he stepped from his plane onto US soil.
Dennis Priven didn't die. Now free of all charges, he got an honourable discharge from the Peace Corps. Officials helped him to get a new identity and a new passport and he joined a government social security department as a computer manager at $80,000 a year. No one he worked with for the next 15 years knew anything about his previous life.
In the early 90s he married a woman of Spanish descent but the marriage lasted less than five years and Priven returned to the apartment previously lived in by his parents who had moved to Florida. Over the years Deb Gardner's family, particularly her stepfather Wayne, campaigned for Priven to be properly punished for what he had done to their daughter. Her mother wanted him jailed for life. Her stepfather wanted him to be hanged.But the US legal authorities have always refused to reopen, or even discuss, the case of Dennis Priven.
After a book was written on the case in 2003, Priven took early retirement and disappeared. His present whereabouts are unknown.
His older brother Jay, who hasn't spoken to Priven since the killing, has his own theories about why his brother has laughed at the law for over 30 years.
"He's played everyone — government, lawyers, friends and enemies — off against each other and walked away laughing. That's what really good poker-players do..."