Prosecutors in the murder case against Scott Peterson (search) exercised their ability Thursday to remove the judge appointed to preside at the trial, contending he is biased against them.

Under California law, the prosecution and the defense each have one opportunity to remove a judge without having to give a reason. A new judge will be appointed by California's chief justice.

Peterson, 31, is accused of murdering his pregnant wife, Laci, just before Christmas 2002 and dumping her body in San Francisco Bay. Her remains and those of the fetus she was carrying later washed ashore.

Prosecutors acted a day after retired Judge Richard Arnason (search), 82, was named to oversee the Peterson case when it is moved from central California to the San Francisco Bay area.

The case is being moved after a Modesto judge ruled Peterson could not easily get a fair trial in his dead wife's hometown.

Deputy District Attorney Rick Distaso (search) said Arnason "is prejudiced against the interest of the party, so that I believe I cannot have a fair and impartial hearing."

Prosecutors refused to elaborate on their reason for removing the judge, said a receptionist in the Stanislaus County District Attorney's office. Peterson's defense lawyer did not immediately return calls seeking comment.

The tactical move will postpone the case that was scheduled to start Monday, said Lynn Holton, spokeswoman for the state's court administration.

Holton said it will take State Supreme Court Chief Justice Ronald George (search) until next week to find another judge for the case.

A hearing is scheduled Friday in Modesto to discuss the transfer to a courthouse in Redwood City and future court dates.

Arnason was selected in part because of his experience handling major trials.