The man convicted of murdering stop-go worker George Taiaroa has failed at getting his conviction overturned by the Court of Appeal.

Quinton Paul Winders was convicted and sentenced to life imprisonment with a minimum period of 17 years following a jury trial in Rotorua last year.

Tairoa was killed with a .22 shot to the head by Winders at close range as he worked on an isolated rural road in the South Waikato in March 2013.

The shooting shocked the nation and with no witnesses, led to a long investigation with Winders eventually convicted largely on circumstantial evidence and sentenced to a minimum of 17 years in jail.

Winders' appeal of both his conviction and his sentence were dismissed in a judgement released on Tuesday.

The appeal related to the evidence of two witnesses called by the Crown about his behaviour in shooting at or near people.

Winders' lawyer argued the evidence dated from the pre-trial stage and should have been disregarded as prejudicial.

During the original trial, Justice Toogood had noted that "the Crown's position that actually shooting at or near people in and around your farm is unusual behaviour, even in the back country of Taranaki".

The second ground of appeal was on statements made by Winders following his arrest on April 4, 2013. In his pre-trial ruling, Justice Kit Toogood held that Winders' detention was unlawful.

However, Justice Toogood also found the statements had not been improperly obtained and even if they had been, would have been admissible.

Philip Morgan QC for Winders wanted the court to reconsider the ruling, arguing that it was wrong and had led to a miscarriage of justice.

Morgan also argued the way the judge dealt with concerns expressed by jurors about the actions of their foreperson during the trial was grounds for an appeal, but the court disagreed.

The appeal also challenged Winders' sentence, contending that a reduction in the minimum period of imprisonment ought to have been allowed to take account of the breach of Winders' rights under the New Zealand Bill of Rights Act when he was unlawfully detained for questioning.

This was denied.

-Stuff