An ESR ballistics expert has told the Bain retrial jury in Christchurch today he believed the shot that killed Robin Bain was more likely to have been fired from a distance of at least 20cm than from close range.
Kevan Walsh carried out test-firings using pork skin in 1997. What he saw on the pork skin with a shot from a distance of 200mm corresponded with what he could see in a photograph of the wound to Robin Bain's left temple, he told the High Court.
Mr Walsh said he was conscious that pathologist Alexander Dempster had carried out the post mortems on the five Bain family members killed by bullets from the Winchester .22 rifle he tested and that Dr Dempster believed the shot to Robin Bain was a close contact wound.
The witness said he had considered whether the silencer could have been against Robin Bain's forehead when the shot was fired.
But he believed what Dr Dempster had taken to be sooting from a close contact wound was a result of bullet wipe, in other words, soot and material from the surface of the bullet as it first made contact with the skin.
From his examination of the photographs he believed there was less blackening round the margin of the wound than would be expected with a contact shot.
Mr Walsh also test-fired the rifle in three different positions to establish an ejection pattern. He said he had been asked to determine if it was possible for a cartridge case to be ejected from a rifle fired on one side of curtains to end upon the other side of the curtains.
He believed if the rifle was fired on the lounge side of the curtains the ejected cartridge was more likely to have hit the curtain and landed on the floor but it was possible it could go through a gap and land on the other side of the curtains or bounce underneath.
The Crown case against 37-year-old David Bain is that he shot his father and made it look like suicide after also shooting his mother, two sisters and younger brother at the family home on June 20, 1994.
But the defence say Robin was the killer and then committed suicide.
Mr Walsh is giving evidence on the 26th day of Bain's retrial on five charges of murder.
