The science of DNA has improved so drastically in the past 15 years it has been used in crime investigations that discrediting DNA evidence now rests mostly on proving it was mishandled or contaminated.
This is the challenge today for lawyers defending Thomas Soria Sr., 39, the Stateline man charged with the March kidnapping, rape and murder of 9-year-old Krystal Steadman.
Defense lawyers are objecting to the acceptance of the DNA testing process used in this case, saying in court documents that a new method, uncontested in court challenges, "is open to question" and that other contests of DNA evidence "have said this science is not trustworthy."
Particularly, they want Douglas District Judge David Gamble to allow a full review of the technology and methodology that led to the Washoe County Crime laboratory's conclusion that Soria Sr.'s sperm was present in samples taken from Krystal's body.
In a narrative filed by investigators, they said the lab "identified Thomas Robert Soria Sr. as the source of sperm cells on the body of Krystal Steadman, as described above, through DNA analysis."
Today's hearing at 9 a.m. in Gamble's Minden courtroom comes in response to a request by Douglas County Deputy District Attorney Tom Perkins for the court to limit the review of DNA evidence to this particular case. "We have a motion pending asking the judge to rule that the DNA method and science is trustworthy and reliable," he said.
In the most recent court filings, attorneys for Soria have not specified areas in which they intend to find evidence of faultiness in the lab's work. Instead, they point out that a machine used in the testing utilizes a unique process.
"When they put the primers into the machine, there's 13 primers rather than one or two primers," defense attorney Michael Roeser writes. "So, technology and the science is open to question and there has been cases cited (in the motion) that have said this science is not trustworthy."
As part of a "discovery" request, Roeser and attorney John Springgate requested maintenance records for the machine, put into use by the crime lab in 1998.
They are also asking whether replacement parts have been added and if cleaning records are available.
The DNA challenge will be key to the ability of the defense to create reasonable doubt that Soria is connected to Krystal's violent abduction and killing, believed to have taken place in his Stateline apartment.
Thomas Soria Jr., Soria Sr.'s 20-year-old son, was sentenced to life imprisonment after admitting his role in the kidnapping and murder of Krystal.
In court documents, the defense says that the findings in the DNA tests are the only evidence that links the elder Soria to the crime.
Testing of blood in a Chevy Blazer that Soria Jr. used to dump the body on the south side of Highway 50, three miles west of Carson City, matched Krystal's genetic fingerprint. Those samples were retrieved by running a swab in the doors and other areas of the car. Also, Soria Jr. was seen carrying a large box to the car, investigators said.
Krystal disappeared March 19 from the Lake Park Apartments where she was seen playing with Soria Jr. Her body was found a day later when a woman told police that she had seen a man matching Soria Jr.'s description throwing something resembling a pillowcase off the edge of the highway. The suspected vehicle at the scene was a Chevy Blazer.
In addition to the DNA review, defendants in October asked Gamble to disallow a computer file that reveals references to actions like those that were believed to have contributed to Krystal's death.
The computer file had allegedly been erased the day of Krystal's disappearance. The computer was found in a closet in the apartment shared by the father and son.
Defense attorneys say there is no proof that Soria Sr. wrote the lewd file and that it might unfairly prejudice a jury. A hearing last month went unresolved when Gamble said he would make a decision at a later date.
As part of a plea agreement that released Soria Jr. from the possibility of a death sentence, he agreed to testify against his father. He is on a witness list, among 80 other names, for a jury trial scheduled to begin at 9 a.m. Jan. 17. Prosecutors have vowed to seek the death penalty against Soria Sr.
What: Thomas Soria Sr. hearing
When: 9 a.m. today
Where: Douglas County District Court