As her loved ones fell sick, one by one, young Frances Creighton was always there to help. With a show of tenderness she sat at their bedsides, nursing them with hot drinks and pudding. And with a look of disbelief, she pondered just why each patient ended up dying anyway.

The neighbors in Newark had their own guesses about what killed Mrs. Creighton’s mother-in-law, father-in-law and brother-in-law between 1922 and 1923: deliberate poisoning. They were right, although it would take another decade and another victim to prove it.