Born in 1964, Noel Crompton Hall lived in Campbelltown, New South Wales, Australia. Details about Hall's early life are limited, but at the time of the crime, Hall was married and employed. There is no publicly available information indicating a history of mental illness or prior criminal activity before the murder.

On December 22, 1987, Hall picked up 28-year-old hitchhiker Lyn Saunders near Gol Gol, New South Wales. After an argument, Hall shot Saunders in the back with a shortened shotgun. When that didn't kill him, Hall placed the shotgun in Saunders' mouth and fired, killing him instantly. The murder remained unsolved for approximately 18 months until a tip-off, following a broadcast on Australia's Most Wanted, led to Hall's arrest. In 1989, Hall was convicted of murder and sentenced to life imprisonment.

While incarcerated, Hall began hormone therapy and, in 1999, was transferred to Mulawa Correctional Centre, a women's prison. Allegations of sexual relations with female inmates led to Hall's return to a male prison after three months. Hall was charged with rape, but the charges were dropped when the alleged victim left the country. In 2003, Hall underwent sex reassignment surgery, funded by a $25,000 settlement from a lawsuit against the state for discrimination based on transgender identity and HIV-positive status.

Hall was granted parole in 2006, but the decision was revoked due to concerns over public safety and lack of a suitable post-release plan. After serving over 20 years, Hall was released on parole in April 2010, under strict conditions, including electronic monitoring and restrictions on contact with the victim's family.