DNA mistakes

It was bad enough when Clark County Sheriff Doug Gillespie had to apologize July 7 for a DNA error that sent the wrong man to prison for four years.

It's hard to pay someone back for four years of his life, though Mr. Gillespie said the department is working on a financial settlement with Dwayne Jackson after determining one of their forensic lab technicians made a mistake while processing evidence following his 2001 arrest on kidnapping and robbery charges.

Who will pay? Taxpayers, of course.

Turns out one of Metro's lab technicians swapped the DNA samples of two cousins, which eventually sent the innocent Jackson to prison for robbery for four years. Police realized the mistake in October.

But it appears the matter doesn't end there. Lab chief Linda Krueger said last week authorities were reviewing as many as 250 cases handled by Terry Cook, who transferred out of the lab in 2004.

And within days, more bad news:

In 2008, numerous mistakes by a Metro lab technician slipped past supervisors and nearly made it into a separate, death-penalty trial, according to court transcripts. The mistakes prompted an audit at the lab of 10 percent of cases over three years, according to the technician's testimony.

"We're taking this seriously and we're now going back and auditing 10 percent of the cases that have been done in the last three years to see if this is an issue in other cases," the technician testified.

While juries, influenced by such TV shows as "CSI: Crime Scene Investigation" have tended to give much credence to forensic DNA, such revelations are "going to substantially hurt the power of DNA in Southern Nevada," says defense attorney Christopher Oram.

"This makes all of us pause about what we're doing," said Clark Count Public Defender Phil Kohn, whose office is now launching a review of DNA evidence in active murder cases and other active cases.

Yes, Metro and the sheriff deserve credit for "coming clean" when they discovered the Jackson mistake -- even if it seems to have taken them most of a year. But saying "human errors will happen" isn't very reassuring. Laboratories are supposed to have procedures in place to prevent -- or at least to catch and correct -- human errors. The public deserves a more detailed explanation of what went wrong -- and what's being done to prevent a recurrence.