DNA testing mistake involves 412 criminal cases

ONE person, one pair of eyes.

The lack of a second level of checks on one occasion led to a blunder in the DNA testing procedure at the Health Sciences Authority (HSA) that involved dozens of criminal cases.

That one individual, a 30-year HSA veteran, slipped up by adding too much of a reagent - a chemical used in DNA testing - impacting the evidence gathered in those cases.

Yesterday, HSA revealed that 412 criminal cases which had DNA samples tested between October 2010 and last August were involved.

But retesting has been ordered on the DNA samples - close to 2,000 of them - of only 87 cases currently before the courts, as a precautionary measure. (See report on facing page.)

The botch-up occurred in 2010 when HSA used a new method of preparing the reagent.

This involved diluting concentrate with water instead of the previous technique of dissolving powdered chemicals in water.

The laboratory manager misread the label and diluted more concentrate, causing the reagent to be 10 times stronger than it should have been.

Ironically, the new method had been adopted to "reduce the possibility of human error" as the number of steps involved was cut down, said the Ministry of Health (MOH) Deputy Secretary Roy Quek during a press conference at MOH yesterday.

The same manager discovered the mistake when preparing the second batch of reagent on Aug 3 last year and alerted the laboratory supervisors.

The police, Central Narcotics Bureau (CNB) and Attorney-General's Chambers (AGC), which have a stake in the matter, were then alerted.

This kick-started an inter-government agency effort to identify the cases for retesting.

"I'm very sorry that this incident took place," said HSA CEO Associate Professor John Lim.

He said that despite the minimal scientific impact as assessed by experts, the impact on the investigational and legal system has been significant and can cause great public concern if not openly and thoroughly explained.

A committee appointed by the HSA board of directors has been set up to investigate the incident, the processes put in place, HSA's risk management procedures and whether further actions should be taken against the laboratory manager.

It will also recommend improvements to processes.

Officer redeployed

Prof Lim said the laboratory manager, a very senior officer with a good track record, has since been issued a warning letter and redeployed pending a further review.

The laboratory, which is accredited by the American Society of Crime Laboratory

Directors/Laboratory Accreditation Board (ASCLD/LAB), has stringent audits in place.

But the audits were not designed to check the concentration level of the reagent used.

Mr Quek said that the reagent had passed tests on its performance, but no testing on its composition or "second-level checks" had been done.

Now, reagents will be sent to another HSA lab to check their composition before being used.

The lab has started purchasing pre-prepared reagents as an additional measure. This, Mr Quek stressed, was something HSA was looking to do even before the boo-boo occurred.

Criminal lawyers told The New Paper this incident should not shake public confidence in the credibility of the criminal justice system here.

"The silver lining is that this appears to be a one-off, isolated incident, and importantly, it does not point to a systemic problem," said lawyer Abraham Vergis.

Criminal lawyer Sunil Sudheesan said DNA evidence is just one facet that the courts take into account in convictions.

He said it was commendable of both the officer and HSA to come clean with the mistake.

Mr Sudheesan said a meeting was held between the AGC and Association of Criminal Lawyers (ACLS) yesterday to discuss how unrepresented accused persons in the affected cases can be helped.

Mr Hri Kumar Nair, chairman of the Government Parliamentary Committee for Law and Home Affairs, said it was important to leave open the option of retesting to the accused persons affected so that they could be assured "everything is above board".

He also said the officer involved and the HSA "did the right thing by coming out in the open with this".

"We would hope that we have a system where we can be open about mistakes rather than a system where errors are swept under the carpet," he said.

This article was first published in The New Paper.