OAKLAND, Calif. — Alameda County District Attorney Tom Orloff is being pressed to take new actions, after additional video footage was made public late last month, showing what happened in the moments before Oscar Grant III, a 22-year-old unarmed African American, was shot in the back by BART police officer Johannes Mehserle early New Year morning.

Mehserle was arrested and charged with murder as public pressure escalated over videos showing him shooting the young man as Grant lay face-down on a BART platform. Last week bail was set at $3 million; at press time the officer remained in jail.

The additional video shows another BART officer, Tony Pirone, punching Grant in the face without provocation, hitting him so hard he fell to the ground. So far, Orloff has refused to pursue charges against Pirone or other officers present during the incident.

“It took two weeks and thousands of people speaking out before the DA charged Oscar Grant’s killer with murder, the Oakland-based internet organization Color of Change says on its web site. “Clearly, it will take continued public pressure to see that justice is served throughout this case.”

Color of Change, founded to empower Black Americans and their allies “to make government more responsive to Black Americans’ concerns and to bring about positive social change for everyone,” is asking the public to sign a letter calling on Orloff to explain his refusal to act on the new revelations. (See www.colorofchange.org.)

The organization is also urging California Attorney General Jerry Brown to place an observer in Orloff’s office while Oscar Grant’s murder is being prosecuted.

“Our focus at this point is the DA doing his job and the Attorney General doing his — in particular, Officer Pirone should be charged based on the video evidence provided and that is not happening,” Color of Change Executive Director James Rucker told the World in an e-mail interview. Asked what more the public can do, Rucker added, “I think calling the Attorney General with very specific requests in terms of what he should do — i.e. force the DA to enforce the law or step in himself — is probably one of the most beneficial acts. Organizing locally, exposing the connection between police unions and the insistence on a lack of oversight are positive acts, too.”

Nor are the people of Oakland alone in their concerns. “In Chicago, in certain communities, the police have been given the authority not just to serve and protect, but to go beyond that,” said Ra Chaka, executive director of the African American Alliance for Peace and Justice. “It’s open season on Black people, not just men, and the same thing happens in the Latino community,” he added.

“We need to be in solidarity across this country,” Chaka said. “We’ve got a new president and he’s trying to do the right thing by appointing some good people to high positions so they can do the people’s business. He’s told us, ‘It’s your job to hold us accountable.’” Obama’s internet system is a way people can get involved to help curb police violence as well as other problems, he said.

In New York City, “the police are out of control,” they are like a foreign occupying force, particularly in Black and Latino neighborhoods,” said City Councilmember Charles Barron, who represents a Brooklyn district. “They are stopping and frisking us, violating our human rights and our constitutional right to move about freely in our neighborhoods.” Barron said in the last couple of years several people have been killed by police in his area, including two unarmed young men who were shot in the back after an altercation at a party.

Barron outlined demands including community control of police at the precinct level, an elected police commissioner, a requirement that police live in the neighborhoods they patrol, and a civilian review agency with power to prosecute police.

Ultimately, he said, economic development and job creation, and not police containment, will bring an end to crime.