Caroline Grills was born in 1888 to father, George Mickelson, and mother, Mary in Balmain, New South Wales, Australia. Her parents named her Caroline Mickelson at birth. Caroline married Richard Grills on April 22, 1908, and they had five daughters and one son.
Authorities suspected her of murder in 1947 four of her family (Christine Mickelson, Angelina Thomas, John Lundberg, and Mary Anne Mickelson) members died. Officials tested the tea she had given two other families (Christine Downey and John Downey) members on 13 April 1953. It was discovered from the results of the tea test that the tea was laced with thallium which is a household rat poison.
- Christine Mickelson was her stepmother who she killed at age 87.
- John Lundberg and 84-year-old Angelina Thomas were her families by marriage.
- Mary Anne Mickelson was her 60-year-old sister-in-law when Caroline killed her.
Caroline Grills was known to serve her family and friends tea, cakes, and biscuits. She started her killing spree in 1947, a year before her father died. She moved to Gladesville after her dad died.
She was convicted on October 15, 1953, of four murders and three attempted murders. The third attempted murder was Christine Downey"s mother, Eveline Lundberg in October 1953. Caroline was sentenced to death for her murders and attempted murders during her killing spree, but her death sentence was changed to life imprisonment sometime later. Caroline was known as "Aunt Thally" to most inmates imprisoned in Sydney"s Long Bay prison.
She died on October 6, 1960, at Prince Henry Hospital at Randwick, New South Wales from peritonitis from a ruptured gastric ulcer at the age of 71 or 72 - depending on her birth month.