A gamekeeper whose shotgun fired and killed a teenager told police officers his work colleague had been "mucking about" with the gun, a court heard.
In police interviews, Ben Wilson claimed the semi-automatic weapon had been left in a safe state by him and could not have gone off without someone tampering with it.
Peter Colwell, of Capel Ucha near Clynnog Fawr, died of a single gunshot wound to the face when the weapon fired.
The 18-year-old was sitting in the back of Wilson's Land Rover, which was parked outside the Ship Inn at Llanbedrog near Pwllheli, when he was killed just after midnight on February 5, 2017.
He was on a night out with Wilson, Benjamin Fitzsimons and two other men, after starting work at the Bodfuan Shoot just a few days earlier.
Wilson, 29, now of Ely, Cambridgeshire, and Fitzsimons, 23, of Nanhoron near Pwllheli, deny manslaughter and are standing trial at Caernarfon Crown Court.
Summaries of police interviews with Wilson and Fitzsimons were read to the jury by prosecuting counsel Patrick Harrington.
The court heard Wilson insist to officers that the gun was safe in the vehicle.
He said he had bought the gun at Christmas and had chosen the weapon because of its safety features.
Wilson said he left the gun in the vehicle between the front seats and near the gear stick. It was upside down with the barrel pointing back. He said the safety catch was on.
A video interview with Wilson was shown in which he demonstrated how the shotgun was loaded, checked and made ready to fire.
He stressed the barrel was clear and there is no way it could be loaded, and added that the gun cannot go off with the safety catch on.
To make the gun capable of being fired, it needs to be cocked in "one smooth easy action" and the safety catch switched to the on-off position, he said.
The video showed the gun would not fire with the safety catch on.
Wilson told the officers that Fitzsimons had been "mucking about" with the gun and his actions had put a cartridge in the barrel.
This had occurred earlier in the evening before the group arrived at the Ship Inn, he said.
Wilson said that, when the group returned to the vehicle after leaving the Ship, Fitzsimons had "gone to it and said 'ha ha' and expected it to go click but it’s gone bang".
Wilson insisted he had left the shotgun safe.
In his interviews with police, Fitzsimons agreed he was the front seat passenger and said the group "got into the truck and it just went bang".
"It was all very quick," he said.
Fitzsimons said he was aware the shotgun was in the vehicle, and said Wilson always had it in the front of the vehicle.
He admitted he had drunk about eight pints of lager during the evening and couldn’t recall events clearly but heard the gun fire.
Fitzsimons added everyone got out in a panic and, on looking into the vehicle, could see Mr Colwell lying on his side.
Dr Brian Rodgers carried out a post mortem on Mr Colwell and found a single entry gunshot wound to the left side of the face.
The court heard it was a significant injury and would have resulted in his instant death, and the cause of death was given as a gunshot wound to the head.
Following the reading of the interviews and the outlining of the facts agreed between defence lawyers and prosecuting counsel, Mr Harrington closed the prosecution case.
Fitzsimons is expected to give evidence in his defence on Friday.
