William Patrick Fyfe was born on February 27, 1955, in Toronto, Ontario, Canada. He was raised by an aunt after his early childhood. In 1958, when he was just three years old, he moved from central Canada to the Parc Extension area of Montreal.

William Patrick Fyfe is a Canadian serial killer known for murdering five women in Quebec between 1979 and 1999. DNA evidence found at the home of one of his victims, Mary Glen, led to his arrest. The Ontario Provincial Police apprehended Fyfe on December 22, 1999, while he was returning to his truck after having a meal at a Husky Truck Stop near Barrie, Ontario.

Fyfe's preliminary hearing started on November 6, 2000. The crown prosecutor handling the case was Jean Lecours. Over time, Fyfe admitted to several murders while he was in custody. However, he only confessed to a part of the crimes he is believed to have committed.

His known victims include Hazel Scattolon, who was stabbed and sexually assaulted in 1981, Anna Yarnold, bludgeoned to death on October 15, 1999, Monique Gaudreau, also stabbed to death on October 29, 1999, Teresa Shanahan, who was killed in November 1999, and Mary Glen, beaten and stabbed on December 15, 1999.

In addition to the murders, Fyfe is also suspected of being the serial rapist known as "The Plumber." This individual was responsible for a series of violent rapes in Montreal during the 1980s. As of now, Fyfe is serving a life sentence in a maximum-security prison in Saskatchewan.