In the late 1940’s, thallium sulphate was a readily available, over the counter poison used by Sydney residents to help cull the rat population during a chronic infestation. “Thall-Rat” became a fashionable ‘murder weapon’ at the time, as it was colourless, odourless and tasteless. The effects were often slow to set in, painful and typically rendered victims hairless, sometimes blind and often lead to nerve damage in hands and feet. Until the epidemic of thallium poisoning was discovered, victims were often mistakenly diagnosed with other illnesses.
Yvonne Gladys Fletcher (1922-) poisoned both of her husbands with thallium. The first, Desmond George Butler, in 1948 and the second, Bertrand ‘Bluey’ Fletcher in 1952. When Bertrand Fletcher became ill with the same fatal symptoms suffered by Butler before he died, Yvonne Fletcher’s family and friends became suspicious. The hospital refused to sign a death certificate for Bertrand Fletcher, and an investigation was ordered which lead to the exhumation of Butler. Both husbands were found to have died as a result of thallium poisoning.
It was reported that Fletcher’s first marriage was unhappy, and her second husband was known to be violent towards her. Fletcher was mother to two children from her first marriage.
At the age of 30, Fletcher was sentenced to death, but this was later commuted to life imprisonment when NSW abolished the death penalty. This was the first known case of conviction for thallium poisoning in Australia. She was released in 1964.
Caroline Grills (1890-1960), best known as ‘Aunt Thally’, is another Sydney-sider-turned-poisoner who used thallium to kill. Between 1947 and 1953, she murdered her stepmother, sister-in-law and two other distant relatives. Her attempt to kill two more family members became her undoing having tweaked to her modus operandi, authorities tested the cups of tea she had prepared for her victims, finding the poison present in both. Traces were then found in the exhumed bodies of her previous victims.
Grills was charged with four murders and three attempted murders (she had also attempted to kill a friend of her mother’s). She was known for her matronly public persona, for being like a ‘favourite aunt’; the motivation for these killings was never quite clear. However, it was alleged at the time that she “was a killer who poisoned for sport, for fun, for the kicks she got out of it, for the hell of it, for the thrill that she and she alone in the world knew the cause of the victims’ suffering.”
Grills was sentenced to death, but this was changed to life imprisonment at Sydney’s Long Bay prison. She died of peritonitis in 1960 and was survived by her husband, daughter and three sons.