**WARNING: This article contains some graphic content.

One of the first police officers on the scene of an alleged murder on a winding Coromandel Peninsula highway has told a jury about how a pool of blood on the side of the road revealed the location of the crime scene.

Adrian Reginald George Phillips, 23, is on trial in the High Court in Hamilton. He is facing one charge of murder in relation to the death of Bayden Williams, 20, who was found dead on the Kopu-Hikuai Rd on the evening of Wednesday, August 5, 2020.

It is alleged that Phillips rammed Williams' vehicle off a twisting stretch of road. When Williams climbed up a bank back to the roadside, about 7pm that night, Phillips allegedly fatally injured him by shooting him three times in the shoulder, thigh and head with a shotgun.

The Crown contends Phillips was in a murderous rage when he fired the shots. His defence counsel says Phillips fired the shots in self-defence, because he believed Williams was coming at him with a knife.

On Monday, the jury heard evidence from constables Benedict Wayne and Blake Wilson, who were working the late shift that night.

Wayne told the jury that he and three colleagues were dispatched to the Kopu Hikuai Rd, at 7.42pm that night to attend a reported shooting incident.

He said they had been tasked with 'looking for a crime scene ... looking for a vehicle crashed off the road and a body”.

About 6.7km up the winding road they found what they were looking for: 'A large pool of blood on the left side of the road ... that was the first thing that we saw”.

Wayne got out and looked down the bank. He saw the form of a crashed Jaguar sedan in the darkness.

”I could see there was a body laying across the front of the vehicle.”

A closer look at the blood pooled on the roadside revealed that it contained what appeared to be brain matter.

With the assistance of a powerful torch, he clambered down the bank towards the car, at one point losing his footing and sliding towards it, but stopping himself before he got to the vehicle.

”I tried not to disturb the scene, but I needed to check for signs of life.”

Wayne checked the man's carotid artery, which had no pulse. He was not breathing, although his skin was warm to the touch. His hair was matted with blood.

The constable rolled back the body to expose the left side of the man's head.

'I could see a penetrating, tunnel-type wound into his head, in front of the left ear.”

Nearby was a spent 12-gauge shotgun cartridge.

'It looked what I would call fresh.”

Not long after, a second police car, a St John Ambulance and police detectives arrived at the scene.

The second police car accidently drove through part of the pool of blood, as the officers either arrived or left to secure a road block to the east, at the turnoff to Whangamata.

Under cross-examination from defence counsel Hannah Stuart, Wayne said he and his colleagues had otherwise been very careful.

'There's an awful lot of people arriving at the scene, aren't there?” Stuart asked. 'Would you say there's a reasonable amount of foot traffic?”

Wayne replied: 'If you were asking if people were trampling, contaminating the scene, no, we were very mindful of preserving the evidence.”

Earlier, the police also heard evidence from Senior Constable Richard Waller, who was off duty when he drove past a ute parked on the side of the Kopu-Hikuai Rd earlier that evening.

Waller said he saw a man by the ute throwing some kind of object into the bush, however he could not tell what it was, other than it was obviously something heavy.

'You would not put that effort into throwing a tennis ball. It was more like throwing a medicine ball.”

-Stuff/Mike Mather.