Friday 26 August 2011
Handling of specimen was flawed, DNA expert tells court
Dr Brian Leslie McDonald told Anwar’s counsel Ram Karpal Singh, who had asked if it was acceptable for a laboratory to accept a sample based on “benefit of doubt”, that it was not acceptable.
Dr McDonald, a defence witness from Sydney, said that if there was a mistake, it had to be corrected and the exact date identified as well as when the change was made.
He said there was no record during the trial that a correction had been made to the labelling of the samples received by Forensics Department chemist Dr Seah Lay Hong.
“You must get it from the horse’s mouth. It must be changed and documented. This is fundamental laboratory practice,” said Dr McDonald.
On Feb 22, prosecution witness Dr Seah testified that she was aware a sample handed to her was dated June 26 when she knew the swabs were taken from complainant Mohd Saiful Bukhari Azlan on June 28, 2008.
She had said that when she received the samples on June 30, she had given them the “benefit of doubt” and did not inform the police.
To Ram Karpal’s suggestion that there had been a mixture of DNA despite prosecution witness chemist Nor Aidora Saedon’s testimony earlier, Dr McDonald said she had reached the conclusion of a single individual profile according to her calculation.
However, he said her calculation was not accurate as the guidelines were not followed when there was a mixture of DNA.
On Feb 25, Nor Aidora told the court that only the DNA profile of Male Y – which had been subsequently identified as belonging to Anwar – was found on a “Good Morning” towel she had analysed and that this was free from contamination.
Dr McDonald also said a sample must be air dried before being frozen, adding that DNA was likely to degrade if it was not properly frozen to the ideal temperature of -20°C.
He also said storing the sample from Mohd Saiful’s anus in a receptacle before air-drying it only made it worse, adding that quantity of sperm also dropped after six to eight hours of ejaculation.
Investigating officer Supt Jude Pereira had said the sample was kept in an air-conditioned room for 43 hours before it was handed to the Chemistry Department.
“If sperm is taken after 56 hours and later kept at room temperature, there will be no sign of sperm,” he said.
Earlier, Solicitor-General II Datuk Mohd Yusof Zainal Abiden had objected to Ram Karpal showing a letter from the American Society of Crime Laboratory Directors that the Forensic Department was not properly accredited as it was not up to international standard.
However, Justice Datuk Mohamad Zabidin Mohd Diah allowed it.
ORIGINAL POST: http://thestar.com.my/news/story.asp?file=/2011/8/26/courts/9373253&sec=courts
Subscribe to:
Post Comments (Atom)
0 comments:
Post a Comment