The SF Police Department bombed the mayor's house in 1975:
"In early August 1975, the SFPD went on strike over a pay dispute, violating a California law prohibiting police from striking. The city quickly obtained a court order declaring the strike illegal and enjoining the SFPD back to work. The court messenger delivering the order was met with violence and the SFPD continued to strike...
The ACLU obtained a court order prohibiting strikers from carrying their service revolvers. Again, the SFPD ignored the court order. On August 20, a bomb detonated at the Mayor's home with a sign reading "Don't Threaten Us" left on his lawn. On August 21, Mayor Alioto advised the San Francisco Board of Supervisors that they should concede to the strikers' demands."
> The Patrolmen's Benevolent Association Riot, also known as the City Hall Riot, was a rally organized and sponsored by the Patrolmen's Benevolent Association of the City of New York (PBA) held on September 16, 1992, to protest mayor David Dinkins' proposal to create a civilian agency to investigate police misconduct. Approximately 4,000 NYPD officers took part in a protest that included blocking traffic on the Brooklyn Bridge and jumping over police barricades in an attempt to rush City Hall. Rioters were observed to be openly drinking, damaging cars, and physically attacking journalists from the New York Times on the scene. Rioters also chanted racial epithets towards the African-American Mayor Dinkins. The nearly 300 uniformed on-duty officers did little to control the riot.
Federal law enforcement (FBI etc) has a tiny amount of manpower compared to local police. In theory the national guard could have been called in but that would be a huge escalation and I doubt the elected officials wanted to go there.
"In early August 1975, the SFPD went on strike over a pay dispute, violating a California law prohibiting police from striking. The city quickly obtained a court order declaring the strike illegal and enjoining the SFPD back to work. The court messenger delivering the order was met with violence and the SFPD continued to strike...
The ACLU obtained a court order prohibiting strikers from carrying their service revolvers. Again, the SFPD ignored the court order. On August 20, a bomb detonated at the Mayor's home with a sign reading "Don't Threaten Us" left on his lawn. On August 21, Mayor Alioto advised the San Francisco Board of Supervisors that they should concede to the strikers' demands."
https://en.wikipedia.org/wiki/History_of_the_San_Francisco_P...