SACRAMENTO — A California Department of Justice expert said Tuesday there’s “strong evidence” that Richard Hirschfield is the donor of DNA material that cracked the UC Davis “sweethearts” murder case, with the chances of another person having the same genetic profile about one in 240 trillion.
“The chance of a random match would be an exceedingly rare event,” senior criminalist Steven Myers testified in Sacramento Superior Court, where Hirschfield is on trial for the Dec. 20, 1980, kidnap-murders of John Riggins and Sabrina Gonsalves, both 18.
Myers’ daylong testimony revolved around four semen stains on a bundle-up blanket discovered in Riggins’ van, which was used in the crime and found abandoned about a mile from the couple’s bodies off Highway 50 and Hazel Avenue in Sacramento County. Their throats had been slashed.
The semen stains went undetected until 1992, when DNA testing available at the time excluded another group of suspects who were being prosecuted in Yolo County. A cold-hit DNA match in 2002 set authorities’ sights on Hirschfield, 63, whose genetic profile had been entered into a national database after his conviction in a 1996 Washington child molestation case.
Myers came on the scene in November 2002, when Sacramento County homicide detectives sent him blood and saliva samples they had obtained from Hirschfield in prison following the DNA hit. Myers also received a blood sample for Joseph Hirschfield, Richard’s younger brother, who committed suicide a day after investigators questioned him about the murders. He left a note that said in part, “my DNA is there.”
Using the samples, Myers developed genetic profiles of the two brothers, comparing them to a DNA profile previously created from the blanket’s semen-stain extracts.
He reported finding the same genetic repeats “in the semen and the profile of Richard Hirschfield, whereas Joseph Hirschfield is eliminated as a possible semen donor.”
The one-in-240-trillion statistic Myers cited refers to the chance of the same profile occurring among the Caucasian population. Among African-Americans, the odds jump to one in 8.5 quadrillion, and among western Hispanics, to one in 1.4 quadrillion.
By comparison, the Earth’s population hovers around 7 billion, Myers said.
Myers’ involvement in the case continued in 2003, when fellow DOJ criminalist Faye Springer — who first spotted the age-darkened semen stains back in 1992 — sent him cuttings from the stained blanket, along with samples of the slain couple’s bloodstained clothing.
He concluded that three of the blanket stains contained a mixture of genetic material “consistent with having the same two contributors,” Myers testified. He said DNA from sperm fractions matched the profile of Richard Hirschfield, while Gonsalves “was included as a minor contributor to those stains.”
The stains contained nucleated epithelial cells commonly found in saliva and vaginal fluid, Myers said. Prosecutors allege Gonsalves was the victim of a sexual assault the night she was killed.
A fourth stain also contained material from two donors, but in this case the major contributor “was consistent with the profile of Sabrina Gonsalves,” Myers said. He also said the minor contributor’s profile was consistent with Hirschfield’s DNA, but noted that other possible donors couldn’t be ruled out.
Myers said he also received the DNA profiles for David Hunt, Richard Thompson and Doug Lainer — the three male defendants in Yolo County’s unsuccessful prosecution of the “sweethearts” case — and concluded that they, along with Riggins, “were all excluded as possible semen donors.”
Hirschfield, who faces the death penalty if convicted, has pleaded not guilty to the murders. His lawyers have contended that Hunt and his associates were responsible for the killings, and that chain-of-custody failures have compromised the evidence in the case.
Assistant Public Defender David Lynch’s cross-examination of Myers, which continues today, sought to raise jurors’ doubts about when, where and how the semen stains came to be on the blanket, and Myers acknowledged his testing didn’t pinpoint any of those factors.
Myers also said he couldn’t rule out the possibility that the epithelial cells on the blanket stains came from sources such as sloughed-off skin or the male donor’s saliva, or that they were deposited on the blanket separately from the seminal fluid.
“All I know is they both got to the same locations,” Myers said.
— Reach Lauren Keene at [email protected] or (530) 747-8048. Follow her on Twitter @laurenkeene