Hiding in the shadows in the early hours of the morning, two members of a specialist police team crept into a driveway to place a tracking device on a grey Ford Explorer belonging to a suspected P cook.

Dressed in dark clothing, Sergeant Don Wilkinson and his partner were unaware they were under surveillance by a CCTV camera system at the Mangere East house and were "sprung" by their target, John Skinner, and his offsider, Iain Clegg, the High Court at Auckland heard yesterday.

The two policemen fled on foot, chased by Skinner and Clegg, who later said they thought the officers were intruders trying to steal a car.

Mr Wilkinson was cornered in a driveway and shot at close range with a powerful air rifle. He died at the scene. His partner, who can be known only as Officer M, survived.

This was the brief summary of the events leading up to the death of Mr Wilkinson, presented by Crown Solicitor Simon Moore, SC, in his opening address to the jury.

Skinner and Clegg have pleaded not guilty to murdering Mr Wilkinson and attempting to murder Officer M.

Skinner has also denied assaulting a third officer, known as Officer W.

The trial of Clegg and Skinner over the death of Mr Wilkinson on September 11, 2008, will give an insight into the secret world of surveillance by covert police operations.

A police veteran, Mr Wilkinson, 46, was a member of the tactical support unit, which helps police squads plant tracking and bugging devices on targets.

After being discovered trying to bug Skinner's car, Mr Wilkinson and Officer M ran into a neighbouring street, where they heard the sound of a powerful car engine.

Mr Moore said Skinner and Clegg "took off" in a Nissan Skyline car which "fishtailed" as they pursued the two policemen.

The officers ducked into the driveway of 41 Earlsworth Rd to hide. The Skyline went past, then reversed, and Clegg and Skinner got out.

"They [the police duo] realised they were in real trouble," said Mr Moore.

Skinner emerged with the muzzle of the airgun pointed at Officer M, standing metres away, he said.

Clegg then struck Officer M in the head with a weapon, breaking his nose and detaching the retina of his eye.

As he fell, he heard the gun discharge, making the soft sound of an airgun rather than the crack of a rifle.

The first lead pellet passed through his left arm. The second went through his thigh, then re-entered his groin and lodged near his hip.

The third hit his back, which was protected by a stab-resistant jacket. He described the impact as feeling like a kick.

"As he lay on the ground, he heard three more shots but was not hurt," Mr Moore said.

"He knew Don was nearby. He could hear him gurgling for some minutes but he was unable to help his friend."

Mr Wilkinson was not wearing a protective jacket and the pellets went into his chest.

He and Officer M were eventually found propped up against a fence. Colleagues checked Mr Wilkinson's pulse. His heart was still beating, but he was unresponsive. Paramedics worked on him for 30 minutes before he was pronounced dead.

Skinner and Clegg told police they believed the two officers were thieves trying to steal Clegg's Skyline. They asked why the police pair didn't identify themselves, and Skinner said he did not mean to kill Mr Wilkinson.

Mr Moore told the court the weapon used to shoot Mr Wilkinson and Officer M was a "destructive" airgun called the FX Monsoon.

It was the same calibre as a .22 rifle, was semi-automatic and was "deadly accurate and extremely powerful" even at 25 metres.

"All in all, this weapon is as serious as it looks," the Crown Solicitor said

Police investigating Mr Wilkinson's killing found chemicals used to manufacture methamphetamine in the house rented by Skinner, and the property "bristling" with security devices.

Mr Moore warned the jury against speculation that the defence lawyers might raise that this was "a bungled police operation and that somehow the officers brought it upon themselves".

"It's very easy criticism to make with the benefit of 20-20 hindsight," he said.

"This is not some sort of inquiry into police actions. It's a criminal trial."

In response to the Crown case, Skinner's lawyer, Marie Dyhrberg, made a brief opening statement on what she said would be important issues in the trial.

She told the jury her client believed the two police officers were burglars, as they were in dark clothing and were acting furtively on Skinner's property.

"John Skinner thought they were intruders," the defence lawyer said.

"It's not a case about someone knowingly harming police officers. It's about as far away from that as you can get."

Ms Dyhrberg also said Skinner did not intend to kill, or injure with the possibility to kill, anyone when he fired the airgun, and self-defence would be raised as an issue.

Stuart Grieve, QC, and Graeme Newell are representing Clegg.

Mr Grieve told the jury that Clegg did not intend to kill Officer M but admitted assaulting him.

"He punched [Officer M] and that is it as far as Mr Clegg is concerned."

Similarly, Mr Grieve said Mr Clegg did not kill Mr Wilkinson.

"He did not have the air rifle and he did not know what Mr Skinner was going to do."

The trial is expected to last three weeks.