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Judge allows GPS evidence in Peterson case

Evidence police gathered using GPS technology to track Scott Peterson’s movements in the weeks after his pregnant wife disappeared will be allowed in his murder trial, a judge ruled.
Susan Caudillo, left, sister of murder suspect Scott Peterson, and their father, Lee Peterson, enter the San Mateo Superior Courthouse for pretrial motions Tuesday morning in Redwood City, Calif.
Susan Caudillo, left, sister of murder suspect Scott Peterson, and their father, Lee Peterson, enter the San Mateo Superior Courthouse for pretrial motions Tuesday morning in Redwood City, Calif.Len Vaughn-lahman / AP
/ Source: The Associated Press

Evidence police gathered using electronic devices that tracked Scott Peterson’s movements in the weeks after his pregnant wife disappeared will be allowed in his murder trial, a judge ruled Tuesday.

The global positioning technology “is generally accepted and fundamentally valid,” Judge Alfred A. Delucchi said.

Because the technology has yet to be tested in California’s criminal courts, prosecutors had to establish both its reliability and demonstrate that the technology was used correctly. Delucchi decided Tuesday they had met those legal tests.

Peterson’s lawyer, Mark Geragos, tried to convince the judge that temporary glitches rendered unreliable the devices that Modesto police secretly attached to vehicles Peterson drove before his April 2003 arrest.

Device called 'good investigative tool'
Hugh Roddis, president of the company that sold Modesto police the three devices, said that covertly placed global positioning devices are a “good investigative tool” and bristled at Geragos’ suggestion Tuesday that police bought cheap devices.

“I think this unit is one of the better ones on the market,” said Roddis, founder of Orion Technologies Ltd., who was testifying on behalf of prosecutors.

The satellite-based radio navigation system can pinpoint locations within feet and is in common use, including in commercial aircraft.

Geragos seized on tracking errors in several of the devices Modesto police used, including one that he said didn’t work for nearly three weeks.

Roddis blamed the errors on inaccurate maps, a faulty wireless antenna and a bad microprocessor connection.

During testimony last week, prosecutors said police used the devices to trail Peterson to San Francisco Bay at least once in January 2003. Police installed the devices in vehicles Peterson owned, borrowed and rented after Laci Peterson disappeared on Christmas Eve 2002. Scott Peterson said he was fishing on the Bay at the time.

If convicted of the murders of his wife and their unborn son, Peterson could face the death penalty.