Police officer Michael R. Smith was fired after making racist comments about blacks, the department said Tuesday.
“He had a history of making racial slurs,” said the police chief, Joseph A. Del Mar. “There was nothing he could do about it.”
Smith was terminated, but he had not been charged with a crime.
Smith’s attorney, Kevin Stankiewicz, said he plans to appeal the firing.
Delmar said the department has fired other police officers in recent months for similar comments.
A department spokeswoman declined to comment.
The city’s police union endorsed Smith’s dismissal, saying the officer made racist remarks on social media and that he is “deeply embarrassed” by his actions.
Smith, 41, had worked at the police department for 10 years.
He was the first African-American officer hired to the department in 2005, and had been the subject of protests and criticism for his treatment of blacks.
A former member of the San Francisco Police Department, Smith was placed on administrative leave last year after an internal investigation found he had made offensive comments to a female officer.
The police union has said it has no plans to endorse Smith’s firing.
Smith has been an outspoken critic of the police, saying police officers are racially discriminated against.
The department has said the officers were justified in using force to remove Smith.
The former officer, a veteran, resigned in 2014 after being accused of sexual misconduct by a female colleague.
DelMar has said Smith is a friend of the department and had supported his hiring.
He said he hopes Smith will find employment elsewhere.