An ESR forensic scientist who found no blood on Robin Bain's shoes when he tested them in 1997 said he was not surprised more recent tests by a defence expert had identified Mr Bain's DNA in a stain said to be blood.
Dr Douglas Elliot told the High Court at Christchurch yesterday the increased sensitivity of DNA technology meant results could now be obtained from very small samples, whereas in 1997, a large amount of material was needed.
But he said while the defence experts believed they had found blood with Robin Bain's DNA on one of the shoes, the DNA could have been from cells deposited in the process of the shoes being pulled on and off over time.
Dr Elliot described visually checking various exhibits in the case in 1997 for possible blood staining.
Of various items of clothing David Bain was wearing on the morning of June 20, only his underpants and running shoes did not have any signs of blood, Dr Elliot said.
Neither was any blood detected on a green jersey or a red sweatshirt, both of which had been washed.
Dr Elliot said he also examined some other items relating to the case in 2003. A green towel and a red towel or bath mat appeared to have extensive blood staining, but the blood was diluted.
And he re-examined the .22 rifle and the curtains from the computer alcove. Fingerprint expert Kim Jones was present when the rifle was examined as were ESR scientists Kevan Walsh and Dr Sally-Ann Harbison and Joe Karam and an associate.
In total, 14 samples were taken from the weapon after probable blood was detected in the rifle groove, on the rifle strap and base of the strap and after chemical testing was positive for blood on the barrel, the forearm, and the silencer.
He found some blood on items of Robin Bain's clothing. That included staining that appeared to have come from a "downward falling spray of blood" on his track pants.
But he found no blood on Robin's socks or shoes.
To defence counsel Paul Morten, Dr Elliot said he was not surprised more recent testing by a defence expert had identified Mr Bain's DNA on one of the shoes, given the advances in DNA technology since his 1997 tests.
Increased sensitivity of testing meant DNA results could now be obtained from very small samples, Dr Elliot said.
