Johannes Mehserle, 27, entered his plea in Alameda County Superior Court in Oakland as about two dozen supporters looked on, including his parents, Todd and Agatha Mehserle. The couple were escorted to court by police officers a day after their Napa neighborhood was evacuated when two suspicious boxes were left on the porch of their home. The boxes turned out to be harmless.

Separated on the other side of the gallery were about 25 relatives and friends of Oscar Grant, 22, the man Mehserle shot on an Oakland train platform. Some, including Sophina Mesa, the mother of Grant's 4-year-old daughter, wore black T-shirts bearing Grant's picture and the words, "Gone but not forgotten."

Deputy Sheriff Lynn Kvikstad, mindful of the intense emotions that Grant's death has stirred, started off the hearing by admonishing everyone not to communicate with Mehserle or make unnecessary comments. "This is going to be a peaceful afternoon," she said.

And it was peaceful, though a few of Grant's supporters taunted Mehserle's friends outside court, shouting "cowards" and "cop killers." They said they could not understand why Mehserle, his attorney or someone else close to the former officer had not publicly expressed any remorse or directed condolences to Grant's family.

Mehserle entered court for about three minutes, but was obscured from the view of most people in the gallery by a security partition. He spoke only to say "yes" three times, in response to questions from Judge Robert McGuiness about whether he waived rights to a speedy trial.

McGuiness ordered Mehserle to return to court Jan. 26, when defense attorney Christopher Miller plans to seek a bail reduction.

Mehserle is now being held without bail, which is common in Alameda County murder cases. He will remain in protective custody, away from other inmates, at Santa Rita Jail in Dublin, officials said.

Mehserle's supporters declined to comment after the hearing. Some of Grant's relatives and friends said they had wanted to look Mehserle in the face and were disappointed that he was behind a partition.

"It's important for Oscar," family friend Jeffery Evans said, explaining his attendance. "We want justice done."

Mehserle was charged with murder Tuesday by District Attorney Tom Orloff, who said Mehserle had committed an intentional, unlawful act when he shot Grant to death at BART's Fruitvale Station. Mehserle and other BART officers had pulled Grant and several acquaintances from a train about 2 a.m. while investigating reports of an onboard fight.

Grant put up a brief struggle, but was lying face-down, with both hands behind his back, when Mehserle shot him, Oakland police investigators said.

Mehserle has not offered a public explanation for the shooting and has declined to talk to criminal investigators. He quit the BART police force Jan. 7 after two years on the job rather than be interviewed by internal affairs inspectors who could have brought a disciplinary case against him.

At a press conference Wednesday, Miller described his client as a "fine young man" and said he expected Mehserle would be cleared.

Mehserle waived extradition in a court hearing in Douglas County, Nev., on Wednesday, a day after he was arrested at a friend's home near Lake Tahoe, where Miller said he had gone after receiving death threats in the Bay Area.

Several legal experts said they could recall no instance of a police officer in California being charged with murder for an on-duty incident, and Orloff said he had never brought such a case in more than 14 years on the job.

Also today, Oakland officials said vandals who broke away from a protest over Grant's shooting in downtown Oakland on Wednesday night shattered the windows of nine businesses and one vacant storefront.

Police made 18 arrests. No looting occurred, and all the businesses were open today.

E-mail the writers at dbulwa@sfchronicle.com and hlee@sfchronicle.com.