DNA, fingerprint experts take stand in Oliver trial

LAKEPORT, Calif. – On Thursday the jury in the trial of a Lakeport man accused of stabbing his neighbor to death heard from DNA and fingerprint experts and a criminologist about the testing of evidence found at the crime scene.

California Department of Justice criminologist Richard Waller, DNA expert Stephanie Carpenter and latent fingerprint expert Terry Hamlin testified Thursday in the murder trial of 34-year-old Ivan Garcia Oliver.

Oliver is charged with murder, burglary, elder abuse and several special allegations for the stabbing death of 67-year-old Michael Dodele on Nov. 20, 2007, at Western Hills Mobile Home Park on Lakeshore Boulevard outside of Lakeport.

The prosecution is alleging that Oliver killed Dodele after finding out he was listed as a sex offender on the Megan’s Law Web site. Oliver mistakenly believed Dodele had molested children, which he hadn’t, although he had done prison time for raping an adult female victim.

The trial began last week. On Wednesday the jury heard an audiotape of a jailhouse interview in which Oliver allegedly admitted to killing Dodele.

Thursday’s testimony included DOJ criminologist Richard Waller, who was able to match a footprint made in blood in Dodele’s kitchen to one of the shoes Oliver was alleged to have been wearing.

Afternoon testimony, which totaled about an hour, included DOJ DNA expert Stephanie Carpenter, who analyzed blood spots on the pants and sweatshirt Oliver allegedly was wearing at the time of Dodele’s death. She also tested blood spots on a knife, bleach bottle, a bathroom water knob and a white rug.

Dodele’s blood was found on Oliver’s sweat shirt, with Oliver’s blood found on the other items, according to testimony.

Carpenter offered the jury an explanation of what DNA is and how testing is conducted.

“DNA is essentially a set of instructions that tells your body how to grow and develop,” she said.

There are the “common” instructions – like how to grow an arm or leg – and then there are the “different” or “highly variable” regions in DNA, which make up less than 1 percent of it and are very different among individuals.

DNA is found in cells – blood, hair saliva, sweat, semen and tissue commonly are tested, she explained.

Carpenter said DNA is contained in the cell nucleus, where 23 pairs of chromosomes are found. Each parent gives half of the DNA. DNA is found tightly wound in those chromosomes.

“I kind of like to think of it as ribbons wound around each other,” she said.

In DNA testing the areas of interest are called “short tandem repeats,” which are highly variable. Carpenter said there are 15 different locations on the DNA that help distinguish between individuals.

Once scientists have a suspected biological fluid, they put it into a small tube and use chemicals to open up the cells. That helps them determine how much DNA they have, the quality and if there are inhibitors, like dirt, in the sample.

Carpenter said they then add a solution to isolate the 15 specific regions and put the DNA through the “amplification” step, which heats and cools it, and allows them to make numerous copies as part of the polymerase chain reaction. They do 28 of those cycles.

From there, the DNA goes into a genetic analyzer, which separates fragments based on size.

When attempting to match DNA, Carpenter said analysts need to have a study that shows how many times certain DNA alleles – an alternative form of a gene – occur at specific locations on chromosomes among major ethnic groups in the population.

She said if a DNA sample has a mixture of multiple individuals it can make the interpretation of findings more difficult. If there are more three three to four contributors, she said they won’t analyze the sample.

Hamlin told the jury that he specializes in dealing with latent prints, which often need to be processed before they can be visualized. They’re prints that typically are left on objects due to oil or sweat on the fingerprint ridges.

He said there also are “patent” prints, which are prints in a foreign substance, like blood or paint.

Hamlin had the known fingerprints of both Oliver and Dodele to use in his analysis.

He was able to find a latent impression on the left side of a blade on a black knife that Oliver is alleged to have thrown out his bathroom window and into a nearby yard. However, Hamlin said that print was of no value because of its condition.

Another print was found on a silver knife that also was found in the yard, but there was not enough of the print to conclude that it was Oliver’s.

Testimony continues Friday at 9 a.m. when the forensic pathologist takes the stand.

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