A Canterbury police officer who repeatedly punched a handcuffed youth in the back of a patrol car has today escaped a conviction.

Timaru constable Marcus John Dominey, 38, was spat at, taunted, and "clearly provoked" when the assault happened in June 2014, a court was told.

Dominey, who was earlier found guilty on one charge of common assault, is now likely to lose his job despite the discharge without conviction, Christchurch District Court heard.

The youth suffered black eyes and a lump on his head.


Dominey, a police officer since 2002 with an unblemished code of conduct record and who had temporarily been promoted to acting sergeant, was charged after his fellow officer complained about the assault. He also testified against Dominey.

Today, Judge Raoul Neave said the officer should be "praised to the skies" for his actions, calling him a "hero".

Defence counsel Pip Hall QC sought a discharge without conviction.

He said it was "realistic" that Dominey, who has also served in New Zealand Army, would lose his job.

A conviction would significantly increase the risk that he is sacked, he said.

He was not aware of a case where a police officer has been convicted of assault in course of his duty and kept his job.

But given the "provocation" and the circumstances, he pleaded with the judge that he would be discharged without conviction so he could restart his life with a "clean slate".

Dominey had interim name suppression but that lapsed today. Mr Hall did not make an application for permanent suppression.

The court heard how Dominey and his colleague had been called out to speak to the victim, and it was likely they had been given a "slightly over-egged account" of his history.

And while that likely contributed to Dominey's approach that day, the victim soon lived up to the level of conduct that was feared.

The youth spat at Dominey and taunted him by saying he was carrying diseases, the court heard.

Judge Neave said the youth's behaviour was "unpleasant, aggressive and risky", and was clearly meant to be provocative.

But while the judge said police have a difficult job, and are entitled to the protection of the legal system and laws, and the right to protect themselves, Dominey's heavy-handed response was "gratuitous and unnecessary".

"It very quickly became a display of testosterone," Judge Neave said.

Given the circumstances of the case, in particular the youth's provocative behaviour, and the "handicap" of a conviction while looking for a new job, Judge Neave granted Dominey a discharge without conviction. He also ordered him to donate $500 to a local Women's Refuge.

Dominey refused to comment as he left court today.