Andres Siordia, clad in red jail garb and wearing black-rimmed glasses, with a dark tattoo on the right side of his neck, listened as Judge Philip Moscone informed him of the murder and attempted-murder charges against him.
Moscone then granted a request by Siordia's attorney to postpone arraignment and plea entry until Monday.
Moscone ordered Siordia held on $2 million bail, as recommended by prosecutor George Butterworth, who has charged Siordia with the murder of Francisco Pena, 41, of San Francisco, and attempted murder for the non-fatal shooting of another San Francisco man, at the pizzeria.
A third man, Francisco Cornejo, 26, of San Francisco, was also shot and killed during what apparently began as a brawl between several people at the pizzeria, but prosecutors have not yet charged Siordia with murder for Cornejo's killing.
Siordia and a 16-year-old boy, whose name has not been released, were arrested minutes after the shootings. The boy remains in custody but has not yet been charged in connection with the shootings.
Butterworth told Moscone today that "there is potential for additional charges" against Siordia.
District attorney's office spokesman Brian Buckelew said after this morning's hearing that prosecutors are still deciding whether to charge Siordia with a second count of murder, and whether charge the 16-year-old, but were pressed for time to file against Siordia before the 48-hour deadline after his arrest.
"I think it was just not enough time to make an informed decision" on the further charges, Buckelew said.
Siordia's current attorney, Rebecca Young, who heads the public defender's homicide unit, said another attorney will be appointed Monday in her place. She said her office is still receiving evidence in the case.
Young said initial police reports indicated there had been "a huge brawl" at the pizzeria.
"At least two people are seen wielding barstools ... at least two people are seen wielding guns," according to witness reports, Young said.
Young said she believed prosecutors did not file a second murder charge against Siordia because the shooting could have been considered an act of self-defense.
She added that the current charges against Siordia could also be seen as self-defense.
"It certainly does have those indications," Young said. Sunday's shooting happened at about 4 p.m. at Papa Potrero's Pizza at 24th and Potrero streets.
Police believe the shooting may have been retaliation for the fatal shooting of Michael Sanchez, 21, of San Francisco, Friday night, during a fight between several people at 24th and Shotwell streets.
No one has been arrested for Sanchez's killing.
Police have increased their presence in the neighborhood in hopes they can stem further violence between what are believed to be separate factions of the Norteno street gang.