But Stock did not give up and forced two inquiries, both of which conceded Tricker's alibi but then concluded that he must have committed the crime the night before even though he had an equally watertight alibi for that time.
Public outrage redoubled and, in early 1870, Stock channelled the righteous anger at a public meeting in Wellington.
"Never have I on any occasion or under the most inspiring conditions heard such a thunder of spontaneous and unanimous applause as that which greeted Mr Stock's appearance on the stage," reporter James Mitchell recalled years later.
"The venerable gentleman's opening words ring afresh in my ears as I write, as though but newly uttered. Raising his hand to still the storm of applause, in almost pathetic tones he said: 'I came not here for your applause, but to seek your assistance to gain justice and liberty for an innocent man wrongly condemned'."
A committee of influential people was formed, and at last, the Government was persuaded to let the wronged man out of jail. He was freed in May 1870 but it was 20 more years before he was finally pardoned.
Arthur Stock is New Zealander of the Year for saving the life and winning the freedom of Walter Tricker, who, but for his intervention, would certainly have been hanged.
From the Herald archives:
'The Rangitikei Murder', New Zealand Herald, 30 August 1864
'The Rangitikei Murder', New Zealand Herald, 19 November 1867
'The case of Walter Tricker', New Zealand Herald, 16 July 1869
Report on public meeting about Tricker case, New Zealand Herald, 16 March 1870
Summary of Tricker case, New Zealand Herald, 14 April 1870
Further reading:
Biography of Arthur Stock, NZETC
'An Old Story Retold: History of a murder case without a parallel', Otautau Standard, 26 February 1907