So this is military officer James Nunn, and he arrived in New South Wales in 1837 with the 80th Regiment of Foot, and this regiment was garrisoned in New South Wales from 1837 through to 1844. The same year that he arrived in Sydney, he became the Commander of the New South Wales Mounted Police.
In December that year, it had been reported that Aboriginal warriors had attacked and killed stockmen on properties beyond the limits of settlement in the Namoi River district, so Nunn was dispatched with two sergeants and 20 troopers and they arrested 15 Aboriginal people along the Namoi River. But they ended up releasing all but two, one of whom was shot while attempting to escape. Then, on January 26, 1838, known as Foundation Day, near the Gwydir River, his party was attacked and a corporal was wounded. In retaliation, the troopers opened fire and a number of Gamilaroi people were killed. The mounted police then pursued them and engaged them again, killing more. This event is now known as the Waterloo Creek Massacre. How many people were actually killed is contentious. Some reports after the event suggested around eight. Others put the figure at around 40 to 50, while the Reverend Lancelot Threlkeld put forward a much larger number of around 200 to 300. Officially reactions to the deaths were slow to filter through to the general population in Sydney. There was strong evidence that the action was unlawful, that procedure was not followed, and that the mounted police went well beyond their powers. However, no convictions were brought against any of the protagonists.
The Waterloo Creek Massacre, just before the Myall Creek Massacre of June 1838, highlights the situation on the Australian frontiers and the wars which were being waged there. As for Nunn, the 80th Regiment was sent to India in 1844 and Nunn died at Meerut on 2nd February 1847, aged 57. His death was reported in the Sydney Morning Herald the following September, reminiscing that, “He was well-known in this colony and universally respected as Commandant of the Mounted Police."