Authorities say it was an unprovoked attack and that the shooter was walking along Center Street with a gun in plain sight -- screaming that he was going to shoot someone.
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38-year-old Ronald Sanders of Oakland was shot and pronounced dead at the scene.
As the gunman was trying to get away, investigators say he fired several shots at two Oakland firefighters who were driving nearby.
"The suspect then, without provocation, fired four rounds at the firefighters, striking their vehicle four times. Three of the rounds were lodged in the driver side door. And one entered the rear passenger compartment and lodged itself in the rear of the driver's seat," said OPD Lt. Frederick Shavies.
The firefighters were not hurt.
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About an hour later, the suspect went into a nearby business, where officers happened to be looking for video of the shooting.
They arrested him.
Police have not released the man's name, but say he has a previous conviction for manslaughter from 1996.
At a vigil Friday evening for Sanders, his mother, Denise Carter, says the death of her son has been traumatizing.
"I am still in shock, and I am numb," she said. "He was always real happy, and got a long with everybody basically he was you know a good guy."
She is calling for an end to gun violence in Oakland.
"We still have our people killing our own people," she said. "Stop the violence. Period."