Court allows racial group profiles
for DNA evidence
By Julia Cheever, Bay City News Service
July 6, 2006
SAN FRANCISCO (BCN) - The California Supreme Court, ruling
in a Solano County murder case, said today that prosecutors can
use profile frequency statistics for different racial groups when
presenting DNA evidence.
The court upheld the murder conviction of William Wilson, 25,
for strangling 13-year-old Sarah Phillips with a telephone cord
in her Vacaville home on April 6, 2000. The decision was issued
in San Francisco.
Wilson was convicted in Solano County Superior Court of first
degree murder with the use of dangerous weapon during an attempted
rape. He was sentenced to life in prison without possibility of
During the trial, a prosecution expert testified about a DNA
comparison of blood found at the crime scene, which showed a match
with Wilson's genetic profile.
The expert, Nicola Shea of the California Department of Justice,
said the match would be expected to occur in one in 96 billion
Caucasians, one of 180 billion Hispanics and one of 340 billion
She described the profile as extremely rare since the world population
is less than 7 billion people. Scientists maintain DNA databases
for different population groups because the odds of a match vary
for each group.
Shea said she gave the statistics for the three different racial
groups to avoid making assumptions about the ethnic background
of the perpetrator.
Wilson, who is African American, argued in his appeal that the
racially differentiated statistics should not have been allowed
in court because there was no evidence about the race of the girl's
But the high court said unanimously that testimony about the
range of racial frequencies can be used so long as the information
is not presented in a manner that assumes the perpetrator is from
a certain race.
Justice Ming Chin, quoting a 2004 appeals court ruling in the
case, wrote, "When the perpetrator's race is unknown, the
frequencies with which the match profile occurs in various racial
groups to which the perpetrator might belong are relevant for
the purpose of ascertaining the rarity of the profile."
The panel said the three groups mentioned by Shea were appropriate
because those were the largest population groups in Solano County.
The panel said a defendant would have the right to present evidence
about statistics for other population groups if he wished.
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