Six days later her father also died. Both deaths were innocently enough attributed to "fish poisoning". However, the small town was about to be scandalised.

David Bestwick had married Mary Jane Foster in Campbell Town on July 29, 1884. Two months later a daughter, Emily, was born.

The family lived in a two-roomed cottage on the verge of the township where David was employed as a labourer.

On Wednesday March 26, 1890, Mary Bestwick prepared a meal for the family which included a tin of Maconochie's tinned herrings. Both Emily and David ate the herrings while Mary only had a mouthful as she had a toothache.

Within 48 hours Emily was dead, and David lost his fight for life on April 3.

Sub-Inspector Palmer began investigating.

Viscera from Emily's exhumed body and David were sent to the government laboratory for examination.

An inquest was held revealing more details. With her daughter and husband dead, Mary was getting "attention" from a jockey called Thomas Thornton, who was and had been a regular caller at the house.

When the Daily Telegraph ran the story, a Launceston chemist, James D Johnston contacted the police with information that Mary Bestwick had bought a box of "Rough on Rats", an arsenic poison on March 24.

Mary explained to the police that the poison was for some dogs that were roaming about the place, but later said she threw the poison from the train window before arriving home as her husband should poison the dogs himself without her help.

On March 27 two fowls belonging to Mary had died and her sister-in-law stated at the inquest it appeared they had been poisoned.

Henry Bestwick said that David had beaten Mary owing to her conduct with Thornton and at one stage Mary had left David and went to live with her mother near the River Forth.

Emily Kearney who nursed David testified that Mary did not pay proper attention to her dying husband and was in and out all night with Thornton.

The government analyst found traces of arsenic in the intestines of the fowls and the stomach of Emily. There was no trace in David's samples, but this was explained by his nine days of purging.

The Coroner's jury found that there was not enough evidence to decide who or how the poison was administered to David.

However, the inquest into Emily's death returned a verdict of wilful murder against Mary. She was arrested and sent to the Launceston Gaol to await trial in the Supreme Court.

The case was heard on June 12, 1890. Mary pleaded not guilty and her representative, R. Byron Miller, gave a superb display of rebutting all the evidence presented by the prosecution.

The jury, after two hours of deliberation, returned a verdict of not guilty.