Ross Farca, the 23-year-old Concord man facing felony charges after allegedly threatening a mass shooting against Jews on an online message board, appeared in court in Martinez on Tuesday morning.

The proceeding was meant to be a preliminary hearing to determine whether there is enough evidence to proceed to trial. But it was postponed for at least two months because a key witness, a detective with the Concord police department, was not available, and because Farca’s new defense lawyer had not been provided all of the case evidence. The court is expected to set a new date for the preliminary hearing on Sept. 26.

The hearing before Contra Costa County Superior Court Judge Theresa J. Canepa had been highly anticipated, particularly after the Anti-Defamation League sent a mass email on July 19 encouraging the Jewish community to show up in numbers. But only a few interested members of the public were in attendance after the ADL, along with other Jewish organizations, sent out a second email saying the hearing would likely be pushed back.

Farca appeared in court with his attorney, Joseph Tully of the criminal defense firm Tully & Weiss. The accused wore glasses, baggy pleated slacks and a purple tie, and had a blond mustache as shown in his booking photo.

He stood silently before Canepa, his hands clasped in front of him, as Tully entered an official notice of appearance on his behalf.

Tully had represented Farca in a civil proceeding against the city of Concord, but had not formally been entered into the record as his criminal defense lawyer.

In an interview with J. Tuesday afternoon, Detective Greg Mahan of the Concord Police Department said his partner, Detective Scott Smith, the witness, was called away to Southern California to testify in a kidnapping case.

Mahan said the police department is aware that Farca has been out of custody since he posted bail on June 14, and officers are “doing the best [they] can.” A court-ordered prohibition on his handling firearms remains in effect. “We just don’t have the resources to sit outside his house, unfortunately,” Mahan said.

In an interview with J. last month, Tully said Farca, who threatened to “mow down” Jews in a Christchurch-inspired shooting on the website Steam, and used the screen name “Adolf Hitler (((6 million))),” has autism, and did not fully comprehend the potential impact of his words.

“In his mind he was not making a threat that he intended anyone to take seriously,” the attorney said. “It’s called trolling.”

But a search of Farca’s Concord home at the time of his arrest on June 10 turned up some disturbing items, including an AR-15-style assault weapon with a magnifying sight, and more than a dozen high capacity magazines, a photo released by the Concord Police Department shows. Officers said a search warrant also turned up “books about Hitler youth and Nazi life,” gun targets, and a 36-inch sword, according to a court filing.

The Anti-Defamation League and the S.F.-based Jewish Community Federation said they have “maintained close communication” with law enforcement since Farca’s release on bail.

“Authorities are focused on mitigating any threat he might pose,” Federation security director Rafael Brinner said.

Several area synagogues and other Jewish institutions have enhanced their security measures as a precaution.

Farca was charged with three felonies, including manufacturing and possessing an illegal assault weapon, and making criminal threats. California is one of seven states and the District of Columbia with an assault weapons ban.

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