Tracking Device Allowed as Evidence at Trial

A judge ruled Tuesday that evidence police gathered using electronic devices to track Scott Peterson after his pregnant wife disappeared can be used in his double-murder trial.

After nearly two days of testimony from experts on global positioning system technology, Judge Alfred A. Delucchi said he believed the devices were reliable -- despite the defense’s objections that they were error-prone.

Because GPS technology has yet to be tested in state criminal court, prosecutors had to establish its reliability and demonstrate that the technology was used correctly.