William MacDonald was born Allen Ginsberg on June 17, 1924, in Liverpool, England. He grew up in a challenging environment during a time of great turmoil in the world. At the age of 19, in 1943, he enlisted in the British Army and joined the Lancashire Fusiliers during World War II. One traumatic night during his service, MacDonald was raped in an air-raid shelter by one of his corporals. This experience had a profound and lasting impact on him.

After serving in the army for four years, MacDonald was discharged in 1947. He was diagnosed with schizophrenia and spent several months in a mental asylum. During his time there, he received electroconvulsive therapy as part of his treatment. Following his release from the asylum, MacDonald changed his name and emigrated to Canada in 1949. Six years later, in 1955, he moved to Australia.

In Australia, MacDonald faced legal trouble shortly after arriving. He was arrested and charged for touching a detective's penis in a public toilet in Adelaide. He received a two-year good behavior bond as punishment. After some time in Ballarat, he relocated to Sydney in 1961, where he worked in construction.

In Sydney, MacDonald found housing in East Sydney. He became familiar in certain parks and public toilets that were known to be meeting places for homosexual men. Same-sex sexual activity was criminalized at the time, leading to these secretive locations.

William MacDonald committed a series of brutal murders in Australia between 1961 and 1962. He killed five men, starting with his first victim, Amos Hugh Hurst, in Brisbane. After a drinking session, he strangled Hurst, punched him in the face, and then hid the body in Hurst's apartment before leaving.

His second victim was Alfred Reginald Greenfield, found at the Sydney Domain Baths. MacDonald lured Greenfield under the pretense of drinking more alcohol. When Greenfield fell asleep, MacDonald stabbed him over 30 times and severed his genitals, disposing of them in Sydney Harbour.

Ernest William Cobbin became MacDonald's third victim. MacDonald met him in South Dowling Street and lured him to a public toilet at Moore Park. There, he stabbed Cobbin repeatedly while he was seated. After the attack, MacDonald also cut off Cobbin's genitals, placing them in a plastic bag for disposal later.

On March 31, 1962, he attacked Frank Gladstone McLean in Darlinghurst. MacDonald convinced McLean to drink with him in a nearby lane. He stabbed McLean multiple times and, believing he was mortally wounded, he mutilated him before fleeing the scene.

The fifth victim was Patrick Joseph Hackett. After drinking with Hackett at his shop on June 6, 1962, MacDonald stabbed him in the neck and heart, killing him instantly. After the murder, he attempted to hide Hackett's body under his shop. When the smell of the decaying corpse became noticeable, police discovered Hackett's body nearly three weeks later.

Authorities connected these murders, and after MacDonald was seen in a different area, he was captured in May 1963. He was found guilty, despite pleading not guilty due to insanity, and received five consecutive life sentences. He served his time in a mental facility until his death in 2015 at the age of 90.