Robert Butler, born around 1851 in either Kilkenny, Ireland, or Bury, England, embarked on a life of crime early on. By 1863, he was already convicted of theft in Victoria, Australia. Over the years, he accumulated numerous convictions for burglary, robbery, and arson across Australia and New Zealand.​

In 1880, Butler was tried for the brutal murders of James Dewar, his wife Elizabeth, and their infant daughter in Dunedin, New Zealand. The family was attacked with an axe, and their home was set on fire. Despite circumstantial evidence linking him to the crime, Butler was acquitted. However, he was later convicted of arson and burglary related to the case and sentenced to 28 years in prison, serving 16 years before his release in 1896.​

After his release, Butler returned to Australia, continuing his criminal activities under various aliases. On March 23, 1905, using the name James Warton, he attempted to rob William Munday in Toowong, Brisbane. During the robbery, Butler shot Munday, who later died from his injuries.

Butler was arrested shortly after the incident, found in possession of two revolvers. He was tried and convicted of Munday's murder on May 24, 1905. Despite his defense claiming illness and hardship, the jury found him guilty.​

On July 17, 1905, Robert Butler was executed by hanging at Boggo Road Gaol in Brisbane. His criminal career, spanning over four decades, ended on the gallows, marking the conclusion of one of the most notorious criminal histories in Australia and New Zealand.​