Robin Bain likely shot from at least 20cm away, trial told

David Bain's defence team says his father shot dead the family before committing suicide. Photo / Pool

A scientist has told the High Court the fatal gunshot wound suffered by Robin Bain was likely fired from a distance in excess of 20cm, adding further weight against theories he committed suicide.

ESR forensic scientist Kevan Walsh said this was his conclusion from viewing photographs of the wound Robin, 58, suffered on the morning of June 20, 1994.

The distance of the rifle from Robin's head is crucial as to whether he could have committed suicide with a .22 rifle found next to his body, or whether he was shot by his son David.

David Bain, 37, is on trial in the High Court in Christchurch for the murder of his parents and three siblings in the family's Dunedin home. His defence team are arguing that Robin shot dead the family before putting the rifle against his head and committing suicide.

Forensic pathology professor James Ferris has previously ruled out suicide based on his view that the rifle was fired between 30 and 42cm from his head.

Dr Walsh told the court said he took note of features around the wound to Robin's left temple, such as unburnt powder particles. He compared these features of test firing done on pigskin.

From these, Dr Walsh said it was possible the shot was a contact wound, with the rifle pressed against the skin, as the defence are arguing.

However having viewed photographs of Robin's wound, Dr Walsh said his opinion was that the shot was most likely fired "from some distance".

"Perhaps a distance of beyond 200mm."

Dr Walsh said tests were also carried out with the rifle in various positions to see how spent ammunition cartridges would travel after being ejected from it, where they would bounce on the ground and where they would end up.

He was then asked to consider whether a spent cartridge ejected from a rifle in the lounge, where Robin was found dead, could have travelled through curtains to an adjoining computer alcove.

This relates to a spent cartridge that was found in the alcove, and whether this could have come from Robin shooting himself, or whether it was from David Bain shooting his father through the curtains from the alcove.

Dr Walsh said the most likely scenario was that if the rifle was fired on the lounge side of the curtains that the cartridge would hit the curtains and fall to the floor in the lounge. However it was possible for a cartridge case to travel through a small gap in the curtains or bounce underneath the curtains.

Dr Walsh also gave evidence about his analysis of white fibres on bullet fragments in the bedroom of David's sister Laniet, 18, who died after being shot three times in the head.

These fibres most likely came from the bullet striking a woven garment or fabric, he said.

The defence has suggested a white cloth was placed over the rifle when Laniet was shot, but this cloth has never been found.