A 21-year-old German sailor on board a New Zealand ship, Arthur Rottman was in the wrong place at the wrong time. At the outbreak of the First World War he was classed as an enemy, and that meant he had to be interned.

But he was allowed to work on a farm – owned by Joseph McCann in Ruahine, New Zealand. Rottman was a popular worker and one of his regular jobs was to take the morning’s milk yield to the local dairy factory.

On December 27th, 1914, he arrived at the factory early. “The farmer’s gone away on a fleecing trip,” he said. A few hours later he left the farm and caught a train to Wellington.

Next day the dairy factory manager was dismayed when neither Rottman nor McCann turned up with the milk yield. The manager set off for the McCann farm and soon found the reason why. Joseph McCann, Lucie McCann and her baby boy were all lying dead in the farmhouse, their heads split open by axe blows.

Rottman was arrested at a construction camp near Wellington. “I am guilty, I know I’m done,” he said. He claimed that the farmer had become angry with him for missing his milk shift, and that he had been drinking heavily. He was found guilty of the triple-murder and hanged at Terrace Jail, Wellington, on Thursday, March 18th, 1915.