Friday, July 7, 2006
Supreme Court Rejects Bid to Exclude Race-Based DNA Evidence
By KENNETH OFGANG, Staff Writer
Proof of the race of the perpetrator is not required as a foundation for introducing evidence of the likelihood, in various racial populations, of finding a random DNA sample matching that discovered at a crime scene, the state Supreme Court ruled yesterday.
The unanimous ruling upholds the first degree murder conviction of William Curtis Wilson in the slaying and sexual assault of a 13-year-old Vacaville girl in 2000.
Wilson had previously dated the victim’s older sister, and was tied to the crime by circumstantial evidence, including testimony that he was seen in the area before the killing, and was later seen with scratches that the witnesses who saw him earlier said he did not have at the time.
An expert testified that DNA obtained from bloodstains on the victim’s clothing matched the defendant’s, and that the same genetic profile would be expected to occur in 1 of 96 billion Caucasians, 1 of 180 billion Hispanics, and 1 of 340 billion African Americans. The victim’s genetic profile was even rarer, the witness testified.
The First District Court of Appeal’s Div. Three affirmed Wilson’s conviction two years ago, rejecting the defendant’s reliance on People v. Pizarro (2003) 110 Cal.App.4th 530.
The Fifth District ruled in Pizarro that evidence of how frequently a DNA match could be expected to occur in samples drawn from a particular racial group was irrelevant in the absence of independent evidence that the crime was committed by a member of that group.
The Fresno-based court reversed the defendant’s conviction for murdering his 13-year-old half sister. DNA testing matched Pizarro’s profile to the profile derived from semen on vaginal swabs taken from the victim.
Pizarro was half Hispanic and half Caucasian. An FBI expert testified that the probability of finding another unrelated Hispanic individual with a similar profile was around 1 in 250,000, while the chances of finding a matching profile in the Caucasian population was 1 in 10 million.
Because genetic profile frequencies within the major racial groups in the United States vary, separate DNA databases are maintained for each group. The expert’s statistics were not relevant, the Fifth District concluded, since there was no independent evidence establishing that the crime was committed by a member of either ethnic group.
Justice Ming Chin, writing yesterday for the high court, said the Pizarro court was correct in condemning the admission of evidence of the odds solely regarding the defendant’s population group, since such evidence, as Presiding Justice James Ardaiz wrote in Pizarro “unjustifiably encourages the jurors to focus on ethnicity and race—specifically the ethnicity and race of the defendant, the only suspect before them.”
But the Wilson court, Chin wrote, was correct in saying that evidence of the odds of a particular profile appearing in various groups was admissible. He endorsed Court of Appeal Justice Joann C. Parrilli’s reasoning that “[w]hen the perpetrator’s race is unknown, the frequencies with which the matched profile occurs in various racial groups to which the perpetrator might belong are relevant for the purpose of ascertaining the rarity of the profile.”
Parilli’s opinion was joined by Justice Carol Corrigan, who was later elevated to the Supreme Court. Justice Paul Haerle, of the First District’s Div. Two, was assigned in place of Corrigan when the case reached the high court.
“When the odds move into the billions and, as with the blood on defendant’s pants, even trillions, the force of this observation becomes ever stronger. In this case, whether the jury focused on the numbers regarding the two blood samples most favorable to defendant (one in 96 billion and one in 110 trillion) or those most damning to defendant (one in 340 billion and one in 610 trillion) is of little moment.”
The justice rejected the argument that the expert’s testimony was too narrow because it included only the three most common racial groups and excluded Asians, Pacific Islanders, and Native Americans, numbers of whom live in the Vacaville area.
The defense, he noted, cross-examined the expert regarding the possibility that the perpetrator, or the person whose blood was found on Wilson’s clothing, might have belonged to one of these groups—she testified that the frequency of those groups would be comparably small—and could have presented evidence of its own concerning other population groups.
The case is People v. Wilson, 06 S.O.S. 3476.
Copyright 2006, Metropolitan News Company