A death in the family: the Croydon poisonings

What happened

Between 1928 and 1929, three members of one family in Croydon, south London, died of arsenic poisoning within roughly fifteen months of each other. Edmund Creighton Duff, who had married into the family, died first, in 1928. His sister-in-law, Vera Sidney, died the following year. Vera's mother, Violet Sidney, died only weeks after her. At the time, none of the three deaths was treated as suspicious. It was only after the third that anyone connected them.

The family lived across two adjoining, unremarkable households on the same street, the kind of respectable domestic setting nobody expected a criminal investigation to reach. Sympathy visits, small gatherings, and shared meals ran through all three deaths, which is part of what made the eventual question so uncomfortable: whatever had happened, it had happened among people who saw each other constantly.

The evidence

Edmund Duff's death in 1928 was recorded at the time as natural, attributed to heart failure, and no post-mortem was carried out. It was only after Violet Sidney's death in 1929, by which point the family had lost three members in a little over a year, that police ordered the two earlier bodies exhumed. Arsenic was found in all three.

Two inquests followed. Both returned open verdicts: poisoning by a person or persons unknown. Investigators looked at ordinary household sources of arsenic, which was a common ingredient in domestic weedkiller at the time and was present in at least one of the gardens, but could not establish how it had reached three people in fatal doses, or who had put it there. Other members of both households were questioned at length. None was ever charged.

How it's been argued over, then and since

The Croydon poisonings drew heavy press coverage at the time, in part because three deaths in one family, all from the same poison, were difficult to explain as coincidence, and in part because nobody could offer a competing explanation that fit all three. The inquest verdicts were never overturned and no prosecution followed either of them.

In the decades since, true-crime writers have returned to the case repeatedly, and several competing theories have circulated about how the poison was administered and by whom, none of them ever tested in a courtroom and none of them proven. What has stayed constant is the formal record: two open verdicts, no charge, no trial, and a family that lost three of its own members without ever being told, officially, why.

Murder Mystery Party's case, A Death in the Family, puts your table inside the same two households, working through the same three deaths and the same evidence the police had. Ninety years on, nobody has closed the file. Yours doesn't have to either.