A 30-year friendship between two men ended with one handcuffing and kidnapping the other, before driving him to a remote hilltop and caving in his skull with a baseball bat and a piece of wood, the Crown has told a court.
Michael Joseph Waipouri - also known as Michael Davies - and Steve Gunbie are on trial at the High Court in Auckland.
Both men are charged with kidnapping Mr Murphy. Mr Waipouri is charged with murdering Mr Murphy. Mr Gunbie is charged with helping him get rid of the body.
In his opening address to the jury, Crown prosecutor Gareth Kayes said Mr Waipouri lived around the corner from Mr Murphy and the pair saw each other most days.
They had been close friends. Mr Waipouri was godfather to Mr Murphy's only son, James, and his partner was a long-time friend to Mr Murphy's wife, who had recently died of cancer.
That all changed in the days before the murder in November 2015 when there was some sort of argument and, according to Mr Waipouri's partner, Mr Murphy was put in his place.
"It was sufficiently serious, whatever happened, that Mr Murphy texted his daughter Christy Thompson, to say he was afraid that Mr Waipouri was going to kill him."
Mr Kayes said Mr Waipouri hatched a plan to lure Mr Murphy to his friend Mr Gunbie's house, north of Warkworth.
Things were cordial with Mr Murphy bringing a box of beers.
"At some point that evening, really out of nowhere, the Crown says, Mr Waipouri attacked Mr Murphy with a bat. According to Mr Waipouri at least, they'd been talking about pig hunting and Mr Murphy had suggested that Mr Waipouri's dog wasn't up to scratch really when it came to pig hunting. And apparently that was sufficient or the only justification required for Mr Waipouri to take a bat to Mr Murphy's head."
Mr Kayes said Mr Waipouri binded Mr Murphy with plastic ties and handcuffs, putting a bag over his head and bundling him into his own car.
Mr Waipouri and Mr Gunbie then drove to a friend of Mr Gunbie's house, near Puhoi. On the way, Mr Murphy managed to escape, but was Mr Gunbie caught him Mr Waipouri hit him again with the bat, he alleged.
Once there, they changed vehicles to drive up a steep hill. At the top, Mr Kayes said Mr Waipouri hit Mr Murphy - first with the bat and then with a tree branch.
"Mr Waipouri later told police that he saw all of the life leave Mr Murphy."
Mr Kayes quoted Mr Waipouri: "I knew he was dead, mate. I just knew, man. Because, as I say, I used to work in a meat processing plant and I used to put animals down with a bar and I know when an animal is dead."
He said after the killing Mr Waipouri and Mr Gunbie left the Puhoi property, but Mr Gunbie returned the following day and rolled the body down the hill.
When Mr Gunbie's friend complained the body was still there, Mr Gunbie cut the seat belts out of his car, tied them together and dragged the body back up the hill before wrapping the body in tarpaulins and dumping it.
Mr Gunbie's friend, who has name suppression, has immunity from prosecution and will give evidence later in the trial.
Mr Murphy's body was found three weeks later after Mr Gunbie's friend came forward.
John Munro, Mr Waipouri's lawyer, told the jury his client was up-front with police and acted in self-defence.
"You will hear and see things during the evidence that will shock you and you may disagree, you may frown upon some of these things, you may be upset by some of these things. These things are a part of our community and we need to deal with them in a fair and compassionate way."
He encouraged the jury to keep an open mind.
Mr Gunbie's lawyer, Adam Couchman, said the jury must assess the credibility and reliability of Mr Gunbie's friend and scrutinise what he said.