An ESR forensic scientist who found no blood on Robin Bain's shoes when he tested them in 1997, said today he was not surprised more recent tests by a defence expert had identified Mr Bain's DNA on one of the shoes.
He put that down to advances in DNA technology since his 1997 tests, Dr Douglas Elliot told the High Court in Christchurch.
One of the advances was the increased sensitivity of the tests which meant DNA results could now be obtained from very small samples, Dr Elliot said. When he carried out his tests in 1997, a relatively large amount of material was needed to obtain DNA results.
But he said while defence experts believed what they found near an eyelet on one of the shoes was a blood stain containing Robin Bain's DNA, the DNA could have come from cells deposited as Robin pulled the shoes on and off over time.
Dr Elliot agreed neither he nor Peter Hentschel, another ESR scientist, had found blood on the shoes in 1997, but ''with DNA technology where it is now'', it would not be surprising to find what the defence located was a stain with Robin Bain's DNA profile.
And in answer to a question from Justice Graham Panckhurst on 36th day of the retrial of 37-year-old David Bain for the murder of his parents and three siblings, the witness said cells giving a DNA result could also be transferred from bodily material other than blood.
And just handling an item could transfer enough cell material to give a DNA result, Dr Elliot told the court.
Bain denies murdering Robin, Margaret, Arawa, Laniet and Stephen Bain, all of whom were fatally shot at the family's Every St home in Dunedin on June 20, 1994.
