In June 1894 Herman Juncken came from Adelaide to Melbourne to settle the affairs of his brother Louis, who had died in May of what was thought to be typhoid. He took his meals at the house on Bridge Road in Richmond kept by Martha Needle, who was engaged to his other brother, Otto. Within days he fell ill after eating, recovered, and fell ill again after breakfast the next morning. His doctor did what none of the doctors in her life had done before: he had Herman's vomit analyzed. It contained rat poison. The police hid near the house, and when Needle served Herman a cup of tea he blew a whistle, and officers came into the kitchen to find her trying to tip it out. The government analyst, C. R. Blackett, found enough arsenic in the cup to kill anyone who drank it.
She was born Martha Charles near Morgan in South Australia, on April 9, 1863, by her death record and some accounts, or in 1864 by others. Her parents separated before she was born, and when she was two her mother married Daniel Foran, described as another brutish man. Police reports later painted an impoverished childhood marked by violence; her mother, an alcoholic with convictions for drunkenness, beat her, a neighbor said, pretty severely at times. After working as a domestic servant, at seventeen she married Henry Needle, a carpenter, in North Adelaide. They had three daughters, Mabel in 1882, Elsie in 1883 and May in 1885 or 1886, and moved to Richmond, in Melbourne, in 1885.
Mabel died on February 23, 1885, aged three, after a short illness; she "seemed to fade," her mother said. Henry died in 1889, Elsie soon after, and May in 1891. Each death was put down to natural illness, and each brought Needle a life insurance payment, sixty pounds on Henry, sixty on Elsie and eighty on May by one account, while she was pitied as a widow who had lost her whole family. In 1891 she sublet the house attached to the Juncken brothers' saddlery at 137 Bridge Road and took in lodgers, and in 1893 she began an affair with Otto. Louis and Herman disapproved and tried to stop the engagement. Louis fell ill in 1894 and died on May 15.
Charged first with attempting to murder Herman, she saw the investigation widen. Louis Juncken's body was exhumed at Lyndoch in South Australia, and those of Henry Needle and the three girls at Kew; arsenic was reported in all five, though one account says May's remains did not test positive. She was tried for the murder of Louis alone. Otto described fits in which she would fall suddenly unconscious, and the defense put forward insanity, but the doctors would not commit themselves, and Justice Hodges rejected it: "the law cannot wait while philosophers, physicians and scientists settle metaphysical problems," he said. "Justice must be swift and sure." The deaths of her husband and children went before the jury as evidence of a pattern, though she was never charged with them. After forty minutes the jury found her guilty, without a recommendation to mercy, and she was sentenced to death. One newspaper wrote that she received the sentence with extraordinary calmness and walked from the dock with a firm step.
Otto visited her in prison and wrote to his mother that he hoped she would be proved insane. A few days after the trial her lawyer, Marshall Lyle, wrote to the Governor. She went on protesting her innocence and was hanged at Melbourne Gaol at eight in the morning on October 22, 1894, the third of four women hanged there. Asked for last words, she said, "I have nothing to say." She left her estate, valued at twenty-five pounds, to Otto, with a letter telling him to think of her "in a happy home with my loved ones, waiting and watching for you." Otto later married, had six children and lived a long life. Her motive for killing her own family was never established.