A state Department of Justice criminalist testified today that Richard Joseph Hirschfield's DNA profile is a one-in-240 trillion match to a semen stain linked to the killings of two UC Davis students 32 years ago.
"This is strong evidence that Mr. Richard Hirschfield is the semen donor," criminalist Steve Myers told a Sacramento Superior Court jury that began its fifth week of work today in the murder trial for Hirschfield.
The 63-year-old defendant is accused in the Dec. 20, 1980, bludgeon and slashing deaths of John Riggins and Sabrina Gonsalves, both of whom were 18 when they were abducted in Davis two days before their bodies were discovered more than 30 miles away off of Folsom Boulevard, near Lake Natoma.
Authorities found the semen stain on a blanket in a van Riggins had been driving the night he and Gonsalves disappeared.
Myers received the blood and saliva samples on Hirschfield from Sacramento sheriff's detectives in November 2002. He completed his report in January of 2003. Hirschfield, already in custody for a sex crime in Washington state, was charged the next year by Sacramento prosecutors with the murders of the two students and the rape of Gonsalves.
Hirschfield faces the death penalty if he is convicted.
Editor's note: An earlier version of this story incorrectly stated the ratio of probability of a match related to Hirschfield's genetic material.