Born in April 1942, at Utrecht, Holland, Hans van Zon was a lethargic child, remembered for his exaggerated courtesy toward adults and his preference for younger playmates. An introverted youth, he was dismissed from several jobs for petty theft and seemed to live increasingly in a fantasy world of his own creation. At age 16, he moved to Amsterdam and bought himself a new, expensive wardrobe, settling down to make his way as a con man and swindler. Van Zon's favorite trick was to pose as a student, bilking sympathetic strangers of cash for a "trip home." Handsome and bisexual, he enjoyed affairs with men and women alike.

Van Zon's first known victim was Elly Hager-Segov, murdered after a date on July 22, 1964. Elly had already taken Hans to bed once that night, and when she rejected his new advances he choked her unconscious, stripped her, and cut her throat with a bread knife.

In 1965, Van Zon reportedly murdered homosexual film director Claude Berkeley, in Amsterdam. (A confession to both crimes was later recanted, with Van Zon asserting that he derived his intimate knowledge of the murders from "psychic visions.") A short time later, he married an Italian chamber maid, living on her wages while he continued his affairs with other women. In 1967, Van Zon's wife told police he was planning to kill her, and he spent a month in jail -- for violating his probation on earlier charges -- before they were reconciled.

On April 19, 1967, Van Zon murdered his occasional mistress, Coby Van der Voort, first drugging her with a supposed aphrodisiac, then bludgeoning her with a lead pipe, stripping her body, and stabbing her with a bread knife. Unsuccessful in his attempt to rape the corpse, Van Zon still bragged of the crime to an acquaintance, ex-convict Oude Nol, and found himself the target of blackmail. In return for his continued silence, Nol demanded that Van Zon "assist" in the murder and robbery of selected victims.

On May 31, 1967, Van Zon entered the fireworks shop run by 80-year-old Jan Donse, clubbing the man to death with his favorite lead pipe before looting the till and dividing the proceeds with Nol. In August, he killed farmer Reyer de Bruin at Heeswijk crushing his skull with the pipe, then slashing his throat for good measure. The crime spree came to an end soon after, when a widow named Woortmeyer -- once romanced by Oude Nol -- survived Van Zon's clubbing and fingered him for police. In custody, Van Zon implicated Nol, and both men were held for trial. On conviction of murder, Van Zon was sentenced to life, while Oude Nol drew a term of seven years in prison.