The gun that shot and killed stop-go worker George Taiaroa was likely a .22 calibre long rifle fired more than a metre away from the victim, a court has heard.
Mr Taiaroa, who was working at the Tram Rd bridge the day he was shot, was killed by a single gun shot injury to the head.
This was revealed by forensic pathologist Dr Simon Stables who conducted the post-mortem on Mr Taiaroa.
Dr Stables was called to the witness stand today in the murder trial of Quinton Winders, the man accused of killing Mr Taiaroa.
He described the track of the bullet as through the centre of the brain and slightly upwards. He said the bullet fragments impacted with the back of the skull and did not cause an exit wound.
Dr Stables said there was no "sooting" or "tattooing" of Mr Taiaroa's wound, leading him to believe the weapon used was fired from at least one metre away.
Sooting or tattooing is markings caused by the discharge of a weapon when fired at close range.
But he added that there were a number of variables that could impact on the pathological appearance of a wound, including the positions of the victim and shooter, the attachment of a silencer to the weapon and whether any head gear was worn by the victim at the time of the shooting.
Dr Stables said Mr Taiaroa's injury was typical of a .22 calibre weapon. He explained this was a low calibre, with high calibre weapons tending to cause exit wounds.
During cross-examination Winders' lawyer Jonathan Temm said it was difficult to distinguish between wounds caused by different low calibre weapons, to which Dr Stables agreed.
Mr Temm reiterated that several things were unknown about the shooting, including the position of Mr Taiaroa, the position of the shooter, the length and type of weapon used, the type of ammunition and how the weapon was held.
ESR forensic scientist Kevan Walsh was also called to the witness stand today to give evidence on the bullet fragments removed from Mr Taiaroa's head as well as scene examinations of the accused's Jeep Cherokee and the Tram Rd bridge.
When examining Mr Taiaroa's body, Mr Walsh noted slight blackening of the gun shot wound but said it was not the kind of sooting or tattooing consistent with close-range shootings.
A microscopic examination of the three bullet fragments led Mr Walsh to conclude the murder weapon was a .22 long rifle.
On April 4, 2013 Mr Walsh went to the accused's parents home where he conducted a visual examination of the Jeep Cherokee, owned by Winders.
He looked for blood and body tissue splatter on the inside and outside of the vehicle but neither was found. Mr Walsh commented on the overall clean state of the vehicle.
Earlier the court heard from Detective Terry Garnett who was involved in the search warrant executed at the accused's parents home near Rotorua on April 4 and 5, 2013.
Mr Garnett was also the officer in charge of a search warrant executed at the same address on April 18, 2013. This was to search areas that were not able to be covered during the first search warrant due to aggressive stags on the property.
Mr Temm said Janet Winders, the accused's mother, told police prior to the first search warrant that her husband, Max Winders, was the only person home and "is quite deaf and not to frighten him".
Mr Garnett said he could not recall speaking directly with Mrs Winders.
Mr Temm went on to say that despite this warning, the Armed Offender's Squad, dressed in black clothing, black balaclavas and carrying weapons, were sent in first to secure the property.
"When you entered the property you found Mr Winders between two Armed Offender's Squad members. He said if you had just told him what you were looking for, he would help you find it," Mr Temm said.
"Yes, he was very helpful," Mr Garnett replied.
A series of statements were also read this morning by the High Court registrar. These covered topics including the search warrant at Winders' parents home, details of Mr Taiaroa's post-mortem and the accused's firearms.
The trial will continue tomorrow.