Peterson: Preliminary Trial

October 30, 2003

DNA debate opens first day

Wiretaps secretly recording Scott Peterson's telephone conversations while he was under police surveillance will not be used in his double-murder preliminary hearing, prosecutors said Wednesday.

Nor will they present evidence from GPS tracking devices placed on his vehicles to monitor his movements, Senior Deputy District Attorney Rick Distaso said moments after the long-awaited hearing got under way in Stanislaus County Superior Court.

The defense, however, still wants to raise the issue that the wiretaps were improperly conducted.

The bulk of Wednesday's proceedings was dedicated to an FBI expert's detailed testimony about mitochondrial DNA testing.

An afternoon of technical cross- examination by defense attorney Mark Geragos was aimed at showing the mitochondrial DNA testing process was unreliable and the results should not be admissable in court.

Geragos also contends that police mishandled a single strand of hair found attached to pliers in Peterson's boat.

Mitochondrial DNA tests showed that the hair did not come from Peterson but could have come from his wife, Laci, according to the prosecution.

Peterson told police he took the boat on a fishing trip to San Francisco Bay on Dec. 24, and his wife was missing when he returned to Modesto that evening. She was almost eight months pregnant at the time.

Her body and that of her son, Conner, were found in April along the bay's eastern shore, several miles from where Peterson said he went fishing. Police arrested Peterson on April 18 in the San Diego area, where his family lives.

Peterson, 31, is charged with murdering his wife and their unborn son, and prosecutors are seeking the death penalty.

Prosecutors are presenting some of their evidence during the preliminary hearing, slated to last five days, and Judge Al Girolami will decide whether there is enough evidence to hold Peterson for trial.

Frey's lawyer can stay

At the outset of the hearing, Geragos asked Girolami to order attorney Gloria Allred out of the courtroom. Allred represents Amber Frey, who was Peterson's girlfriend when Laci Peterson disappeared.

Frey, 28, of Fresno has cooperated with authorities since she contacted police on Dec. 30. She said she did not know that Peterson was married when they began their relationship.

Girolami allowed Allred to stay but ordered her not to discuss any testimony with her client.

"You can give her advice but you cannot include what witnesses have said," Girolami said.

All witnesses are kept out of the courtroom before testimony. Exceptions are the parents of Laci and Scott Peterson and Laci Peterson's sister, Amy Rocha.

Prosecutors gave no indication of when they intend to call Frey to the stand.

The prosecution's first witness was Constance L. Fisher, an FBI expert on DNA analysis.

Fisher explained the difference between nuclear DNA, which is found in the nucleus of a cell and positively identifies tissues, and mitochondrial DNA, which is found elsewhere in a cell and is less specific.

Mitochondrial DNA is passed down from one's mother, and all maternal family members share the same mitochondrial DNA, Fisher said.

FBI lab technicians used mitochondrial DNA analysis to show that a hair found in the pliers in Peterson's boat was not his and may have come from his wife. That could be crucial if authorities attempt to show the boat was used to transport Laci Peterson's body.

The hair could have come from Laci Peterson's mother or brother, according to Fisher's testimony. Amy Rocha has a different mother.

Geragos spent most of the afternoon going over technical details of Fisher's analysis. Under exhaustive questioning, she said that FBI protocol on such testing has evolved over the years.

Observers packed the 70-seat courtroom Wednesday. Many yawned during complex, technical testimony after lunch, and some appeared to doze off.

Geragos asked many questions about contamination and others based on hypothetical situations.

Fisher said tissues from the same person might test differently if samples were taken years apart. She noted FBI protocol prohibiting her from opening an evidence envelope at one point in testing, to prevent contaminating the hair in question, or the possibility that another hair might enter the envelope.

1 strand becomes 2

Geragos contends that one strand of hair became two after two Modesto police officers checked out the hair from the evidence locker. Prosecutors contend that the single strand simply broke inside the evidence bag.

State law requires a special hearing to determine the validity of a novel scientific technique. Girolami, agreeing to hold such a hearing, noted Wednesday that California courts have not accepted such DNA analysis in cases in which it was offered for forensic evidence.

Prosecutors called Fisher to demonstrate that the process is generally accepted by the scientific community. Twelve state courts across the country and one federal court have ruled that mitochondrial DNA is admissable, according to prosecution documents.

"The court will see that there is nothing new and novel in this particular type of technique," Senior Deputy District Attorney Dave Harris said.

Fisher testified: "Children are learning this in high school. They're doing this in biology labs across the country."

FBI analysts compared the hair found in Peterson's boat with one of his blood samples and to DNA on a test swab designated as "SR2." The hair matched the DNA sample from the swab.

Under cross-examination, Fisher revealed that the swab came from Laci Peterson's mother, Sharon Rocha.

It did not match Scott Peterson's blood sample, contained on a test card, Fisher said. Authorities are likely to have obtained the blood sample after obtaining a warrant for Peterson's "person."

Based on a comparison of the DNA from the hair strand to an FBI database, Fisher said one in every 112 Caucasians would be expected to have the same DNA sequence, as would one in every 159 Hispanics.

Under questioning, Fisher acknowledged that she had never testified in California state court and that this was the first case in which she was testifying specifically about the admissibility of mitochondrial DNA evidence. She has testified 14 times on other DNA-related issues.

At the end of the day, Scott Peterson's mother, Jackie, exited the courthouse holding onto Geragos' arm.

"We're glad it's getting started," she said. "We're praying for wisdom for the court."

Bee staff writer Garth Stapley can be reached at 578-2390 or

Bee staff writer John Coté can be reached at 578-2394 or

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