Scientists testify about DNA in third week of Aguirre trial – The Spokesman Review

Scientists from a private laboratory who pioneered forensic DNA testing testified Monday about how and why a condom collected as evidence in 1986 near the body of strangulation victim Ruby Doss was discarded three years later after DNA had been extracted.

The handling of DNA evidence has emerged as a key part of suspected killer Richard Aguirres defense.

The testimony of scientists Michael Baird and Lisa Bennett came during the third week of Aguirres trial in Spokane. The two worked at LifeCodes, a private laboratory on the cutting edge of forensic DNA science in the late 1980s, Baird said.

It was really at the beginning of DNA testing for identification in forensic testing, he said.

Baird was involved in developing the protocols for the lab, he said, which included guards against contamination. The lab was not credentialed in forensic DNA testing in 1989 because, he said, that type of credential did not exist yet.

At the time they used restriction fragment length polymorphism testing, Baird said.

That required a microgram of DNA. Now the most common type of DNA testing requires about 1,000 times less DNA to be successful, Baird said.

Bennett conducted the DNA testing on the condom in 1989. She testified she attempted to obtain a DNA print from the condom.

Upon examining the condom, she could not see any semen with the naked eye, so she put the entire condom into a test tube with clarified water to wash off the DNA from the inside and outside of the condom, which she said was not out of the ordinary for the time.

Bennett then disposed of the condom and continued working with the solution that contained the DNA.

I felt I got all the DNA off that I was going to get off by processing it per protocol, Bennett said.

She attempted to separate the sperm DNA and nonsperm DNA, but ultimately, there was not enough DNA for testing with the technology available at the time, Bennett said.

Aguirres attorney, Karen Lindholdt, questioned Bennett extensively on reagent blanks, which are vials of the solutions used in testing kept separately to show a lack of contamination.

Bennett and Baird said it was not common to keep blanks like that at the time, despite being required now.

While Lindholdt asked numerous questions related to contamination of evidence and documentation of chain of custody, Bennett was firm that nothing was amiss in her handling of the evidence based on protocols of the time.

Im not aware of any case that I violated any protocol processing or that I mixed things, Bennett said.

LifeCodes protocols were not available for the prosecution or defense to examine, which Lindholdt argued made it impossible to know if procedure of the time was followed.

Following the scientists testimony, Lindholdt renewed her motion to exclude the DNA evidence, noting the lack of protocol document and lack of accreditation, among other issues.

The fact is, there were lots of chances for contamination of the condom bag, Lindholdt argued. That lab is the genesis of everything we are talking about in this case, and it was 1989; it wasnt accredited.

Prosecutor Larry Haskell argued that it was the inception of DNA testing, and that time has faded the scientists memories and made the protocol unavailable, all of which could go to the weight of the evidence but not exclude it.

He also noted that more testimony regarding contamination was expected.

Spokane County Superior Court Judge Jeremy Schmidt ruled that evidence will remain admitted and he would consider the issues raised by Lindholdt as part of the weight he will give the evidence.

Huma Nasir, who conducted DNA testing on the case in 2008 while working at private lab Orchid Cellmark, also testified.

She found a full male DNA profile in the condom extracts, Nasir said. That profile later matched Aguirre.

Nasir also found partial male DNA profiles on Doss pants and her left hand. Those did not match Aguirre.

Nasir was unable to obtain a profile from the female portion of the condom extracts.

Additional testimony on the DNA evidence is expected Tuesday. Aguirres trial is scheduled to continue through mid-December.

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Scientists testify about DNA in third week of Aguirre trial - The Spokesman Review