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Judge allows GPS evidence in Peterson case

Defense attorneys had argued that data weren't accurate

Scott Peterson appeared to take many notes during the hearing.
Scott Peterson appeared to take many notes during the hearing.

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Scott Peterson's attorney wants tracking evidence suppressed.
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Scott Peterson
Laci Peterson
Crime, Law and Justice
San Francisco (California)

REDWOOD CITY, California (CNN) -- The judge in Scott Peterson's murder trial ruled Tuesday that evidence dealing with the electronic tracking of Peterson after his wife's disappearance will be admitted in the trial.

"The generic methodology is generally accepted and fundamentally valid," Judge Al Delucchi said in his ruling, referring to the information that came from global positioning devices placed on Peterson's vehicles.

Delucchi also ruled that the prosecution must disclose to the defense the location of the antenna used in the tracking. The prosecution will tell the defense the location of the antenna privately, and the judge will then decide if that information will be heard in open court.

The prosecution objected, saying that is privileged law enforcement information.

Peterson's attorney, Mark Geragos, argued that the information gathered through global positioning system technology was not accurate. GPS uses signals from dozens of satellites to show a receiver's position to within a few feet.

"If the FAA will not approve GPS for the landing of an aircraft, how can a court of law approve its forensic use in a capital case?" he said.

Geragos had also questioned whether the placement of the devices could have prevented them from accurately reporting Peterson's position.

Peterson, 31, is charged with killing his pregnant wife, Laci, and their unborn son. Their bodies washed up separately on the shore of San Francisco Bay in April 2003. Prosecutors have said they would seek the death penalty if Peterson is convicted.

After Laci Peterson vanished in late December 2002, police in the couple's hometown of Modesto placed GPS units on four vehicles used by Scott Peterson to track his whereabouts.

Hugh Roddis, president of Nova Scotia-based Orion Electronics, which made the GPS devices, said he was never told where the devices were placed.

"I assume the antenna positions were fairly good," Roddis said. If not, he said, the tracking maps he reviewed would have reflected more gaps or errors in their transmissions.

The GPS units would reorient themselves and correct their readings automatically at the beginning of each hour, he said.

In one case, an error was an entire degree of longitude -- about 60 miles. As a result, the device briefly indicated the vehicle had traveled 38,000 mph, but soon corrected itself.

Geragos focused on a nearly three-week gap in readings from one device that resumed transmitting after a technician replaced its antenna, according to Modesto police. The device was later sent back to Roddis' company to replace a faulty microprocessor.

A prosecution witness testified last week that the GPS devices, despite briefly malfunctioning at least four times, accurately tracked Peterson to San Francisco Bay between the time his wife was reported missing and he was arrested.

Peterson told police he was fishing in the bay December 24, 2002, the day his 27-year-old wife disappeared, and had launched his boat from the Berkeley Marina. The bodies washed ashore a few miles from the marina.

Prosecutors say the GPS evidence is circumstantial but indicates Peterson behaved as if he were guilty by driving to San Francisco Bay in January 2003, possibly fearing someone would find the bodies.

Other issues

Geragos successfully argued to relocate the trial from Modesto in Stanislaus County to Redwood City in San Mateo County last month because of pretrial publicity. (Full story)

Now he wants the jury sequestered for the four- to six-month trial, claiming the new venue is more hostile than Modesto.

Geragos claims extensive media coverage has hurt Peterson's chances of a getting a fair trial and that jurors should not be further exposed to it once they are selected.

Geragos cited billboards along the highway near the court as examples of how ubiquitous the coverage is. The billboards depict Peterson in an orange jumpsuit after his arrest and ask, "Man or Monster?"

"The jury pool may be so minute we may be conducting jury selection in a phone booth," Geragos said.

"You might be right," the judge responded, smiling.

He also ruled that the prosecution may not call a witness in the trial who was hypnotized to elicit information.

Geragos also wants a separate jury to determine the penalty if Peterson is convicted, contending people who qualify for death penalty cases often favor the prosecution. He argues his point with the judge, who has not yet ruled on the motion.

Delucchi has said he would address Geragos' request to sequester the jury this week.

No date has been set for the start of jury selection.

CNN's Rusty Dornin contributed to this report.

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