Gregory John 'Bluey' Brazel was born on November 17, 1954, in Blacktown, New South Wales, Australia. He grew up in a typical Australian family. Information about his early childhood is limited, but he eventually joined the Australian Army in 1974. He trained at the 1st Recruit Training Battalion in Kapooka and was assigned to 14 Platoon B Company. By September of that year, he was posted to the Australian Army Medical Training School in Healesville, Victoria.

During his time in the army, Brazel showed signs of instability. In 1976, during an army medical corps exercise in Healesville, he took five privates hostage. This incident involved the firing of shots before he was convinced to release the hostages. Following this event, Brazel was dishonorably discharged from the army.

After leaving the army, Brazel faced various legal issues throughout his life. His early experiences in the military and subsequent actions would later play a role in shaping his life and reputation.

On May 28, 1990, Gregory John Brazel murdered Sharon Taylor while he was out on early release from prison. Her body was found in a shallow grave at Barongarook, Victoria, south of Colac on September 23, 1990.

Just a few months later, on September 13, 1990, Brazel killed Roslyn Hayward in Sorrento. Her body was discovered later, on October 1, 1990.

Earlier, on September 20, 1982, Brazel shot Mildred Teresa Hanmer during an armed robbery at her hardware and gift store in Mordialloc. She died later in the hospital from her injuries. This murder remained unsolved for many years. In August 2000, nearly eighteen years later, Brazel confessed to killing Hanmer while seeking a deal with the police.

Brazel was arrested on September 26, 1990. He was later convicted of two murders in 1992 and 1993, as well as the murder of Mildred Hanmer in 2005.