The mother of a teenager accused of killing a prominent attorney's wife was arrested on suspicion of being an accessory to murder on the same day her son appeared in court to face a first-degree murder charge.

Esther Fielding's (search) seat in the front row of the courtroom was vacant Thursday as her son, Scott Dyleski (search), 16, appeared before a judge on charges that he fatally beat and stabbed Pamela Vitale (search), the wife of well-known defense attorney and television commentator Daniel Horowitz (search).

Dyleski stood behind a protective glass barrier during the brief court hearing, as his case was reassigned temporarily to the public defender's office. He did not enter a plea.

Defense attorney Thomas McKenna (search) asked the judge to remove him from the case, saying that neither Dyleski or the boy's father wanted him on the case. McKenna defended the driver of a car that killed Dyleski's half-sister and another passenger in 2002.

"He understands I need to withdraw from the case," McKenna said of his client.

Fielding, 53, was being held in lieu of $500,000 bail, according to a deputy at the Contra Costa County Jail. Authorities did not release details of her arrest.

Court documents filed Tuesday mentioned some of Fielding's involvement in the case.

Dyleski was at his girlfriend's Walnut Creek home on the night of Oct. 15 when he called Fielding, who told him to spend the night there because the road was blocked by "police activity within the area," according to an affidavit filed in support of a search warrant for the girlfriend's house.

The affidavit also said investigators seized a duffel bag from a vehicle at Fielding's house that contained clothing items and a glove, both with traces of blood.

"It appears as though some clothing items are still missing, as well as the stabbing instrument believed to have been used in the commission of the crime," Detective Cary Goldberg wrote.

Sheriff's spokesman Jimmy Lee didn't return pages seeking comment on Fielding's arrest Thursday.

Dyleski was arrested Oct. 19, four days after the killing. Vitale's body was found by Horowitz in a mobile home on the Lafayette hilltop estate where the couple were building their 7,000 square-foot dream home.

Also Thursday, Contra Costa County Judge David B. Flinn issued a temporary gag order until a Nov. 10 hearing, after attorneys on both sides sought to keep the case out of the media spotlight.

Lee said he received more than 200 media calls about the case on one day last week.

Horowitz was a popular legal pundit who received national attention for his commentary during the double-murder trial of Scott Peterson (search), convicted last November of murdering his pregnant wife. At the time of his wife's death, Horowitz was defending Susan Polk (search), a woman accused of killing her husband, in another high-profile case.

In a move likely to bring Vitale's case even more attention, Los Angeles attorney Gloria Allred (search) has been retained by an unidentified witness in the case.

Dyleski was arrested after police received a tip from a neighbor who said his credit card was stolen, which led detectives to Dyleski. The credit card was allegedly used to buy hydroponic growing equipment — often used to cultivate marijuana — that was scheduled for delivery to the Horowitz residence, according to police documents.

Investigators believe Dyleski went to the home looking for the equipment and got in a fight with Vitale, an investigative source who requested anonymity told the San Francisco Chronicle last week.

In the Tuesday affidavit, a Contra Costa County Sheriff's detective said he was looking for a murder weapon "that could cause blunt force trauma," blood samples, hair fibers, a stabbing instrument, among other evidence.

The affidavit also detailed some of Dyleski's activities on the night of Oct. 15. He reportedly went to a friend's house with his girlfriend for about an hour, before the couple left for the girlfriend's house "in order to have sex," the affidavit said.