KCBS_740 SAN FRANCISCO (KCBS) — A day after the San Francisco police officers’ union president sent an angry letter to the 49ers and the NFL demanding that Colin Kaepernick apologize for his criticism of police in explaining why he will no longer stand for the national anthem, protesters supporting Kaepernick showed up outside the union offices.

The Justice For Mario Woods Coalition, members of the ACLU, the Nation of Islam and Elaine Brown, the former head of the Black Panthers, stood outside the San Francisco Police Officers Association headquarters Wednesday in solidarity with Kaepernick.

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“Your threatening communication to the 49ers, and the NFL against brother Colin will not be tolerated. We condemn you as we stand with brother Colin,” Brown said Wednesday.

About three dozen people came to support Kaepernick outside the SFPOA Wednesday.

“I’m very proud of him. He needs to know that we stand with him,” said protester Maria Gutierrez.

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“The POA cannot dictate the speech of an American, an African American, or anyone else,” said civil rights attorney John Burris.

The embattled 49ers quarterback has won some new allies lately in his fight for racial justice, and one of them is even a Raiders fan.

“Even though I’m a Raiders fan, and I’ve never supported Kaepernick in the past, but I do on this. What he’s saying is valid – it’s important – and I support his right to say it,” Raiders fan Mark Jacobs told KCBS.

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The SFPOA issued a statement saying it respected the protesters’ right to free expression, adding:

Police officers around the U.S. show up for work every day to protect the First Amendment rights of protesters. Today is no different. San Francisco police officers will be on duty to make sure that the protest remains peaceful and that the protesters are kept safe.

There’s no doubt that we disagree with some of the more outrageous arguments made against our union by the protesters. But the bottom line is that the SFPOA is one of the most diverse police unions in the country, and our 2100 members are committed to fighting racism in all its forms. Racism is not welcome in our ranks.