The trial of a man accused of killing George Taiaroa is expected to heat up today with the first of the Crown's key witnesses expected to take the stand.

Quinton Winders, 45, has pleaded not guilty to killing 67-year-old Taiaroa, who was shot dead while operating a stop-go sign at roadworks in Atiamuri, north of Taupo, in 2013.

George Taiaroa was killed while operating a stop/go sign near Atiamuri in 2013.

Today is day three of the month long trial at the Rotorua High Court. The jury has been told how a minor traffic accident sparked a series of events that ultimately led to the death of George.

During her opening statement, Crown prosecutor Amanda Gordon divulged some of the events leading up to that day – including a minor traffic accident at the scene a week earlier.

It involved Winders and his father, Max, backing into another car, causing minor damage to their car.

A witness would come forth to say Winders said, "if the stop-go guy had been doing his job properly, the accident wouldn't have occurred," says Amanda.

"No one heard the shot, but the coverage that followed resonated around New Zealand."

Amanda also described the moment when Taiaroa's body was discovered by a truck driver, who saw him beckoned over to the window of a blue Jeep Cherokee from which he was shot at.

"He [George] was then seen to immediately fall to the ground, the blue jeep cherokee then sped off.

"To his horror, he discovered George had a bullet hole in his forehead."

Amanda says the identification of the driver of this car would also unmask the killer – and that Winders owned a blue Jeep Cherokee.

She further claimed Winders had attempted to change the appearance of his car and lied about his whereabouts at the time of the murder.

"Evidence when put together will establish Quinton Winders was the driver of that Jeep Cherokee," she says.

"The defendant and the murderer drove a blue Jeep Cherokee."

Quinton Winders in the dock during the start of his trial in the High Court at Rotorua. Photo: Mark Taylor/FAIRFAX NZ.

Winder's counsel Jonathan Temm, QC, says his client lacked motive for the killing and points to a number of issues he says supports his client's innocence.

"The most obvious one: the complete absence of motive.”

"Is this man here, this man, the man who shot the deceased?" says Jonathan, pointing to Winders as he addressed the jury.

"He doesn't know Mr Taiaroa, never met him, no dealings with him, no motive to kill him."

Jonathan also took issue with the differing descriptions of the car seen at the scene, and the police investigation into his client.

"He [Winders] was the only focus ... police haven't followed the evidence - they've made him their target.

"The defence is going to show you there is other evidence they've simply ignored."

Jonathan also argued it is hard to believe Winders made a 500km round trip "in order to kill a man he's never met, never spoken to and had no reason to kill".

"The police are not always right and the correct place to start is: Mr Winders is innocent."

Speaking to the jury ahead of the trial, Justice Kit Toogood says the burden rested with the Crown to prove Winders' guilt.

"In this case it is inevitable you will feel sympathy for George Taiaroa and his family ... but you must not allow the sympathy to intrude in any way on your interpretation of this case

"Unless and until you decide otherwise, you must presume Mr Winders is not guilty."

The jury also heard evidence from two witnesses, Michelle Anne O'Donnell and Bridget Louise Scully, who were in the car involved in the accident with the Winders.

It was Michelle who says she heard Quinton Winders blame Taiaroa for the accident.

"[He said] the accident wouldn't have happened if the road worker had been doing his job properly. He didn't say it with any malice or anger, he just stated it.”

The court also heard a statement from George's eldest daughter, Rochai Taiaroa, read by the registrar, who says she was unaware her father had any enemies.

"[He was] a loving husband father and grandfather, he avoided conflict wherever possible.”

The first witness today will be construction superintendent Andy Searancke, who will be cross examined by Jonathan. He was questioned yesterday by the Crown.

Truck driver Craig Clothier is also expected to be called today. He was the first witness to discover Taiaroa had been shot.

- Additional reporting Stuff.