SALINAS, Calif. — Forensic DNA consultant Elizabeth Johnson finished her testimony in the Kristin Smart murder trial Wednesday after a rigorous cross-examination challenging her qualifications.
Johnson previously testified she did not think the human blood protein tests performed by Angela Butler, a senior forensic DNA analyst with the Serological Research Institute in Richmond, were reliable.
This was because there have not been verification studies on how the test reacts with blood aged for more than two decades or blood in soil and the fact that different parts of the same sample yielded different results, she said.
The soil samples were extracted from beneath the deck of Ruben Flores, Paul Flores' father, who is also charged in the case.
Investigators believe Ruben Flores helped hide Smart's body after Paul Flores killed her and that, at one point, her body was buried underneath the deck.
When it came to the DNA found on the mattress cover presumably from Flores' dorm room, she came to the same conclusion as Butler: Neither Flores nor Smart could be included or excluded from the sample taken from a small stain.
The main difference between Johnson's and Butler's opinions on the mattress cover was whether the data extracted from the stain should be considered separate from data taken from the sample around the stain.
Butler testified the stain should be considered different, but Johnson said it should be considered the same.
On his cross-examination, San Luis Obispo County Deputy District Attorney Chris Peuvrelle focused on Johnson's qualifications, noting that she had not worked in a lab since 2003.
The lab she did work in was not accredited by any lab accreditation organization, Johnson testified.
Johnson's work since 2003 has focused primarily on consulting on legal cases, with some consulting on labs, she said. She has only testified on behalf of the prosecution one time, she added.
When asked how much the defense was paying her to consult on the case, Johnson said she was being paid $250 an hour before her testimony and $2,000 a day for the two days she was on the stand. She estimated her bill to the defense will be around $6,000 to $7,000.
On the one known study that has been done on how the blood tests react with blood exposed to the elements, Peuvrelle noted trace amounts of blood were still found accurately with the tests.
Johnson replied that the blood tested in the study was not aged 20 years.
Peuvrelle asked if she knew whether the blood had been in contact with or buried under soil, covered by a deck, blocked on one side by a house or blocked on one side by lattice work.
Johnson said, to her knowledge, these were not factors in the study.
When it came to the email Johnson sent Christian Stadler, a German scientist who works for the company that manufactures the blood test used by Butler, Peuvrelle noted the parts Paul Flores' defense attorney left out.
According to the email exchange, there are no validation studies pertaining to the test's ability to accurately read samples exposed to soil for more than 20 years.
"Generally, I would say that after 20 years there is no hemoglobin left due to degradation. Maybe in a dry desert on shady place," Stadler wrote to Johnson.
He added the test could react "invalid" if the pH is too high or too low, but the buffer that is required to be used with the test should prevent that outcome.
Brent Moon, who was subpoenaed by the defense, also took the stand Tuesday.
He said he was dating Jennifer Hudson in 1996 — the year Hudson said Flores told her he killed Smart.
He testified the two would often go to a San Luis Obispo house that had a skateboard ramp in the backyard, consistent with what Hudson had also said.
The backyard is where Hudson said Flores told her he killed Smart and "put her under his place in Huasna," she testified earlier in the trial. Moon was skateboarding on the ramp and did not witness the conversation, she said.
That was the first and only time Hudson saw Flores at the house, she said.
Moon said he did not know Flores and did not recognize him as a skateboarder or someone who frequented the house.
Hudson never talked to him about Flores or what he allegedly said, Moon testified. She also never told him about anyone confessing to the murder of Smart.
This is consistent with Hudson's testimony, which was that she only ever told her former roommate, Justin Goodwin, in 2002.
There was a point in 1996, however, when Hudson stopped going with Moon to the house with the skateboard ramp, Moon said, which was "a little" surprising because she always went with him.
Hudson had also testified that she followed Flores to drop off acquaintances at a skateboard ramp in Huasna. Moon said he did not skate at a ramp in Huasna in 1996.
Court adjourned around 3 p.m and will resume with more testimony from defense witnesses on Monday.
