An overseas ballistics specialist has shown a High Court jury in Christchurch how Robin Bain could easily have shot himself with the Winchester .22 rifle used in the Bain family shootings in 1994.
Philip Boyce, a United Kingdom forensic firearms expert, used the murder weapon to demonstrate how someone of Robin Bain's build could have held the gun to inflict the same wound as the one that killed the 58-year-old school principal.
With the assistance of Joe Karam, long-time campaigner for Robin's oldest son David Bain (37), Mr Boyce showed how someone of Robin's height and approximate arm span would have been able to reach the trigger of the rifle and shoot themselves.
For the demonstration, Mr Boyce wore a special skull cap with an attached steel rod which imitated the trajectory of the bullet path from the rifle into Robin's head.
The steel rod was inserted in the rifle barrel to obtain the 45-degree angle.
Using several possible positions standing, leaning over the rifle, with his foot and his knee on a chair and the rifle butt on the chair and on the floor - he showed he could still reach the trigger.
Even with his shorter arm span, he still had 3cm to 4cm to spare, the witness said.
He told the court his height made no difference to the calculation, as he was working on the length of the rifle and the arm span of the individual.
Crown witnesses have told Justice Graham Panckhurst and the jury they thought it was most unlikely, if not impossible, for Robin Bain to have been able to shoot himself with the rifle.
The Crown says it was David Bain who shot his parents and three siblings, then set the scene to implicate his father.
But the defence says Robin was the killer of 50-year-old Margaret, their daughters Arawa (19) and Laniet (18) and their younger son Stephen (14) and that he then turned the gun on himself.
Mr Boyce also told the court about tests he carried out in his UK laboratory, using a colleague as a model for similar reconstructions with the rifle and using the special helmet.
That person was about the same height as Robin Bain, although with a slightly shorter arm span, and had no problem reaching the trigger of the rifle.
If the person had actually shot himself in a standing position while leaning forward, he would have expected him to fall backwards.
Had he been leaning a little further forward over the rifle, he would have toppled forward.
Contrary to what was shown in Hollywood films, a person would not be thrown across the room by the force of the shot, but would crumple and fall backwards, Mr Boyce told the court.
He said the position of Robin Bain's body on the floor, and the position of the rifle, as shown in photographs of the scene, was "quite consistent with people shooting themselves as demonstrated".
As to whether the wound to Robin Bain's left temple was a near contact or more distant wound, Mr Boyce said his opinion it was a contact or near contact, with the rifle's silencer virtually against Robin's head.
The "sooting" around the wound was an indication of that.
He could see no indication of any burnt or unburnt particles of propellant around the wound.
Crown pathologists said the wound was at least an intermediate one, although Dr Alex Dempster who carried out the post-mortem examinations said he thought it was contact or near-contact because there were no powder abrasions.
But, like the other two Crown pathologists, he thought it unlikely, if not impossible Robin had committed suicide.
One of the pathologists, Dr James Ferris, had used a wound to Laniet Bain's cheek as a guide to Robin's wound in terms of the distance the firearm was away, but Mr Boyce said he had seen pictures of that wound and believed, because of the partially-burnt propellant around the wound, that it was an intermediate one, with the rifle being between 20cm and 30cm distance from the skin.
Asked about a wound to the top of Laniet's head, Mr Boyce said he believed that was the first of the three wounds inflicted on her.
He said that particular wound could not have been inflicted while she was lying down.
The wound was approximately 15mm in diameter, which, he said, was unusual for a .22 calibre rifle.
The court was told earlier that wound would have been fatal.
Cross examined by Crown counsel Robin Bates, Mr Boyce agreed he had no formal medical training as such, that his expertise was in ballistics.
Asked whether a right-handed person, as Robin Bain was, would be likely to shoot himself in the left temple or the right side of the head, the witness replied "I can't really say".
He agreed even if the wound to Robin Bain's head was close contact, that did not rule out homicide and if it was an intermediate wound and not close contact, that would not necessarily rule out suicide.
He said the furthest the rifle could have been away from his head so he could still reach the trigger would be 18cm to 22cm.
"But you didn't do that testing?" Mr Bates asked.
"No.
"I did tests calculated on his arm span and the length of the rifle," Mr Boyce replied.
On trial
The trial of David Cullen Bain (37) continued at the High Court in Christchurch yesterday.
Bain denies murdering his father and mother, Robin and Margaret Bain, sisters Arawa and Laniet and younger brother Stephen at the family home in Every St, Dunedin, on June 20, 1994.
The Crown, represented by Kieran Raftery, Cameron Mander and Robin Bates contends Bain murdered the family, using his early morning paper round as an alibi to make it look as if Robin Bain shot them before Robin committed suicide.
But the defence, represented by Michael Reed QC, Helen Cull QC, Paul Morten and Matthew Karam, argues Robin was the killer and turned the gun on himself because he was about to be exposed for an incestuous relationship with his younger daughter Laniet.
The trial, before Justice Panckhurst and a jury of seven men and five women, began on March 2.
The Crown closed its case on May 6 and the defence began its case on May 8.
