Scott Peterson's preliminary hearing in the killing of his wife, Laci Peterson (search), and their unborn son was postponed Thursday until September.

During a scheduling hearing in Stanislaus County (search) superior court over search warrants, wiretaps and a gag order, Judge Al Girolami (search) set the preliminary hearing for Sept. 9 after prosecutors said witnesses were not available next month. Defense lawyers agreed to postpone the hearing that was scheduled from July 16-18.

District Attorney James Brazelton has said he will seek a public preliminary hearing against Scott Peterson instead of a secret grand jury proceeding to dispel rumors and "open some eyes."

If the judge decides to keep the hearing open to the public, it will be the first time that evidence in the case has been discussed in open court and will determine if Peterson should stand trial.

Peterson, 30, has pleaded innocent to two counts of murder and could face the death penalty if convicted. He was arrested after the remains of his wife and unborn son washed ashore in San Francisco Bay in April near where he said he was fishing Christmas Eve when she disappeared.

Comments Brazelton made to The Modesto Bee last week about his reason for seeking an open preliminary hearing were also on the agenda Thursday as defense lawyer Mark Geragos claims that the prosecutor violated a court gag order barring attorneys, witnesses and investigators from speaking about the case.

Geragos has asked that Brazelton be found in contempt of court and has asked the judge to set a hearing in that matter.

Geragos is also challenging the use of court-ordered wiretaps to eavesdrop on Peterson's phone conversations. The defense claims investigators improperly listened to protected lawyer-client discussions and wants the evidence thrown out and prosecutors kicked off the case.

Brazelton's office said snippets of privileged conversations were overheard inadvertently and they would not be used as evidence.

Reporters whose phone interviews and messages for Peterson were also captured on the wiretaps are seeking to listen to those conversations.

The proceedings, held just days after the six-month anniversary of his wife's Christmas Eve disappearance, were also expected to discuss the sealing of another search warrant in the case.

All search warrants and most police reports on file with the court have been sealed in the case and the court has been closed when evidence has been discussed.