WSP crime labs slip up

SEATTLE – The Washington State Patrol’s crime labs have recurring problems with DNA contamination and errors, an investigation by the Seattle Post-Intelligencer has found.

Through public records requests and interviews with defense attorneys and experts, the paper found that forensic scientists made mistakes while handling DNA evidence in at least 23 cases during the past three years. Human error is apparently the main problem.

In eight of the 23 faulty cases, forensic scientists tainted tests with their own DNA. They made mistakes in six others, ranging from throwing out evidence swabs to misreading results. Tests were contaminated by DNA from unrelated cases in three instances, and between evidence in the same case in another. The source of contamination in five other tests is unknown.

The WSP contends strict protocols make sure the incidents only represent a fraction of the 1,400 DNA cases handled each year.

“We’re as good as any lab and probably better than many,” said Barry Logan, director of the crime labs.

Although the labs only recently set up a mandatory reporting system for mistakes, officials are “100 percent certain that with all the precautions we catch everything,” said Gary Shutler, who supervises the lab system’s DNA work.

Cells in the human body contain a copy of a person’s unique DNA, or deoxyribonucleic acid, which determines a person’s eye color, height and other inherited characteristics. A DNA match is considered infallible proof of guilt or innocence in many crimes.

Sophisticated DNA testing has played a crucial role in high-profile cases, such as connecting Gary Ridgway to the Green River murders.

Crime lab officials do not like to talk about the fact that the same test that can link someone to a crime scene with a few tiny cells left on a doorknob can also be contaminated by a passing sneeze, the paper said. They also do not brag about the fact that DNA tests are only as reliable as the person doing them.

“The amazing thing is how many screwups they have for a technique that they go into court and say is infallible,” said William C. Thompson, a forensic expert and professor of criminology and law at the University of California-Irvine, who reviewed the incidents at the request of the P-I.

“What we’re seeing in these 23 cases is really the tip of the iceberg,” Thompson said, explaining that the lab is only catching obvious problems that could signal a more widespread problem.