A cottage burns down, three mutilated bodies are found inside and there are fears the whole city of Auckland could be at risk. In this episode of Black Sheep, William Ray investigates the story of the first European to be judicially executed in New Zealand history.

October 10th, 1847. The brutal murder of a Devonport family leaves Auckland fearing an invasion of vengeful Māori. But when that threat fails to materialise the police are left trying to solve New Zealand's first ever whodunnit...

It began just after midnight, when lookouts on the HMS Dido spot flames rising from the house of Lieutenant Robert Snow.

The sailors rush ashore and extinguish the blaze but after, find the badly mutilated bodies of Lt. Robert Snow, his wife Hannah and their four year old daughter, Mary.

Pieces of flesh had been cut from all three bodies. The sailors know what that means... Cannibalism.

The New Zealander (one of Aotearoa's very first newspapers) is quick to lay blame for the murder of the Snow family:

"There can be no doubt that the natives were perpetrators of this foul deed. Our native police pronounced the wounds to be Maori handiwork at once. The mutilation of the bodies, from all three of which large pieces of flesh had been cut by knives, and the parts from whence they were cut, is conclusive evidence."

The only controversy is whether the Māori killers were motivated by personal revenge against Snow, or if this is a precursor to a wider attack on Auckland itself.

As The New Zealander put it: "If the matter be political, this act, according to Maori custom, is a declaration of war."

Most of the prominent Māori chiefs who live near Auckland are equally convinced the murders were committed by Māori and are even more anxious than the European colonists to find the perpetrators.

"Chief Patuone over on the North Shore was very friendly towards Pakeha and chief Te Whero Whero in the Northern Waikato was also" says Terry Carson, author of The Axeman's Accomplice - a book about the Snow family murders. "They were quite keen that nothing interfere with the relationship" he explains.

Māori leaders assure the colonists that they will track down the person responsible and at first they have some success. A few weeks after the murders a group of prominent chiefs from Ngāti Maru and Waikato-Tainui arrive in Auckland with a prisoner; a man called Mamuku, who they say killed the Snows.

Mamuku is publicly interrogated on the veranda of Government House, but the questioning quickly reveals he knows nothing about the murders.

Police and Māori are stumped. But then, a break; the killers give themselves away…

Go to this episode on rnz.co.nz for more details