At an early afternoon briefing, Oakland Mayor Ron Dellums said it is important "that we look to the family to determine whether the standard of justice has been met" because they have lost the most and that it was clear that Grant’s family felt "disappointment," "great pain" and "extraordinary hurt."

Mehserle, who is white, contended that he mistakenly used his firearm instead of an electric Taser weapon when he shot Grant, who was black. But prosecutors argued at his trial that Mehserle meant to reach for his handgun as he tried to handcuff an unresisting Grant, who was lying face-down on the platform floor.

Johannes Mehserle, 28, was sentenced Friday by a Los Angeles County Superior Court judge to two years in prison for the shooting of Oscar J. Grant III on an Oakland train platform in the early morning hours of New Year's Day 2009.

Oakland officials said they are ready if things get unruly Friday night in the wake of what some protesters have called the lenient sentencing of a former BART police officer for the fatal shooting of an unarmed man.

"One can draw from that that the test of justice in their mind's eye was not met," Dellums said. "I want you to know that I as a human being understand that. I understand the anger. I understand the pain. I understand the hurt. I understand the disappointment. One cannot live here for nearly 75 years as I have and not understand that."

While promising that residents will be able to protest and voice their anger and disappointment, Dellums said "it is my legitimate hope that that is not destructive to ourselves, it is not destructive to our community."

Oakland Police Chief Anthony Batts would not enumerate at the afternoon briefing the size of the police presence, but he did say that his department is fully deployed and ready for whatever unrest might occur.

At 2:30 p.m., about 175 protesters had gathered at City Hall and had a previous permit; at that point, there had been no incidents of violence. Batts said officers plan to "surgically remove" vandals from the crowds of protesters and that plainclothes police will be videotaping the crowds all afternoon to help in arresting and charging anyone who commits a crime.

"We have numbers of police officers deployed in many places where they are not visible," he said. "We have plenty of resources.... We will do everything we possibly can to make sure that the city is not damaged and that we do this in an orderly fashion."

[Updated at 4:45 p.m.: At a 4:30 p.m. briefing at the city’s Emergency Operations Center, Chief Batts said officers had identified more than a dozen people in the crowd Friday who were involved in "dysfunctional illegal activity" in July during rioting after Mehserle was found guilty of involuntary manslaughter.

Law enforcement agents from around the region were visible downtown, he said, talking to demonstrators and "urging them to participate in a very peaceful way."

Asked about calls for violence during the Grant protest at City Hall, Batts said, "if those are voices of people who don’t live here, I hope the people who do live here drown them out."

The crowd had grown to about 250, he said, and remained peaceful.

At the pro-Grant demonstration in front of Oakland City Hall, protesters were angry and tearful but not surprised by what they viewed as Mehserle's light sentence.

"The first word that comes to mind is just heartbreaking," said Kanika Ajanaku, 65, as she wiped her eyes. "Over the course of 400 plus years that people of African descent have been in the Western Hemisphere, we have never been able to get justice."

Grant’s death at Mehserle’s hand "reminds me of Abner Louima at the hands of the NYPD, and the lynchings of hundreds," she said. "There’s no justice for us in this society. I don’t know how much more of this society expects us to endure."

Wesley Burton, 32, was watching news coverage of the demonstration from his home near City Hall when he decided to come out and see it for himself. Burton, who works for a marketing company, derided Perry’s decision.

"It wasn’t much of a sentence, I don’t believe," Burton said. "He’ll do a few more weeks, a couple of months more, and then go on with his life.... I guess there's some progress. Fifteen years ago, without the technology, there wouldn’t even have been a trial."]

-- Maria L. La Ganga in Oakland

Photo: Mehserle in court. L.A. Times