In 1909, Martha Rendell was tried, convicted, and hanged for one of the most extraordinary and horrific crimes seen by WA Police.

Rendell was the common-law wife of Thomas Morris, and she cold-bloodedly murdered three of his children by swabbing their throats with spirits of salts. Although the children died slow and agonising deaths, they had been treated by a number of Doctors during their illness; only one of whom had expressed any doubts on their deaths.

The crimes only came to light in early April 1909 when a brother, George Morris, was reported missing, and neighbours expressed concern as his two sisters and a brother had died in suspicious circumstances. Detective Sergeant Mann and Constable Lamond took over inquiries and found George at his Mother's home. He claimed to have run away because his step-mother had killed his siblings and was trying to poison him with spirits of salts.

The inquiry was hampered by the period of time that had elapsed since the deaths and because doctors could not say what effect swabbing with spirits of salts would have. Suspicions were further aroused when it was shown that Rendell had purchased large quantities of spirits of salts during the period of the children's illnesses, but none since the last death. Armed with this information the Detectives obtained permission to exhume the bodies and this was done on July 3, 1909.

Autopsies showed that a poison had been administered, and this had caused inflammation and haemorrhage of the bowel. However, it was not until dozens of witnesses had been questioned that a neighbour gave evidence that through a window, she had seen Rendell swabbing Arthur Morris's throat and had heard his agonised screams and cries for help. On a visit to Rendell she had smelt the bottle and experienced strong fumes and burning, but Rendell claimed that a doctor had prescribed the medication.

As there was no scientific evidence of the effect of swabbing with spirits of salts, Mann prevailed upon the Department of Health to experiment on rabbits and guinea pigs. This proved that such swabbing would bring about the effects seen by the autopsies.

No motive could be found apart from Rendell's infatuation with Morris and her anger at the children's disobedience.

Although Thomas Morris was also charged with the murders, he was acquitted as it was believed that, although he had purchased spirits of salts, he had not been aware of the crimes until after the children's deaths. However he had lied to police and to the Coroner, and the Jury wanted to find him guilty of being an accessory after the fact, but this was not allowed.

Rendell was hanged in Fremantle Prison at 0800 hrs on October 6, 1909. At no stage did she show any remorse for her despicable crimes.