He was born Allan Ginsberg in Liverpool, England, in 1924, was raped by a soldier during his national service, and emigrated to Australia in 1955. He drifted between cities and jobs and names, and settled on William MacDonald.
He killed Alfred Greenfield, a vagrant, on a beach at Domain Baths in Sydney in June 1961, stabbing him repeatedly and cutting off his genitals. He killed William Cobbin in a Brisbane lavatory in November 1961, Frank McLean in a Darlinghurst lane in March 1962, and Patrick Hackett, who had been sleeping in the storeroom of the Sydney mixed-business shop MacDonald was then running, in November 1962. Each was mutilated the same way. The Sydney press called him the Mutilator, and the killings caused a degree of public alarm that Australia had not seen before. The Sydney press called him the Sydney Mutilator.
The five were Amos Hurst, fifty-five; Alfred Reginald Greenfield, forty-one; Ernest William Cobbin, forty-one; Frank Gladstone McLean; and Patrick James Hackett, forty-two.
He then did something unusual. He left Hackett's body under the shop, planted his own identity documents on it, and disappeared, and the body was buried as William MacDonald. The deception held until the smell brought the police back, and even then it took months.
He was living in Melbourne under another name when a former workmate from the railways recognised him in the street in April 1963 and told police, who did not believe it, because MacDonald was dead. He was arrested, tried in Sydney, and convicted in September 1963. He was declared insane shortly afterwards and held in Morisset psychiatric hospital, then returned to the prison system in the 1980s. He never applied for parole and said he did not want it. He died at Long Bay on May 8, 2015, aged ninety, having served fifty-two years.