Come on. Uppity blacks? The Black Panther Party was a revolutionary group advocating the armed overthrow of the United States government. They also advocated killing white police officers in black communities as they were "agents of oppression," sent there by the racist state to keep black people down.
Remember, Off the pigs!
I remember it very well, much more so than you might realize.
The local environment at the time this went down was chock full of nuts from every side of the political spectrum, from Minutemen and the Klan (yeah, the Klan was in California) to every type of leftist from Trotsky to Stalin to Mao, Anarchists, and just plain pissed off people.
Without overstating it, and I'm absolutely no fan of any armed nut, in certain communities at the time, LEO's were much more prone to use force, up to lethal.
Some of the causation in both Oakland and S.F. that brought about the Panthers was the fact that if you were a young black guy, it didn't take much in either city for you to end up in the tank with a busted head and a felony charge (not just blacks either. there was a local case involving the HA's where the DA charged a member for breaking the leg of a LEO - cop claimed he witnessed the angel do it with a coke bottle...tv news footage of the incident showed the angel in question being clubbed on the head by an OPD officer, and when the 6' 8", 300 or so pound angel fell on the other officer, that's how the officers leg ended up being broken.)
It had been the law prior to the Panthers' day trip to the capitol that unless otherwise restricted by local ordinance, an individual could openly carry a loaded handgun on their person - not in SF or LA, but in many other places people could and did - leading to shock on the part of Los Angelenos or SF residents that went up the gold country, but it was legal.
What the Panthers pulled in Sac, was street theater of the highest order, and it did exactly what it intended, which was garner publicity.
They eventually devolved into a flat-out criminal operation, that's an absolute truth, but they were also on the receiving end of massive local, state and federal scrutiny, not all of it Constitutional or legal, and the fact that they were black, outspoken and armed made them an enemy of the public order even if their only public act would have been the free food program for the community that was one of their earliest programs.
Contrast what the history was of the Panthers v what the history was of other armed subversive groups of the era, and especially look at the reaction of the FBI was to the various players - the FBI had eyes and ears in the Klan and didn't do much of anything when the Klan killed blacks or white civil rights volunteers, even to the point that they had CI's in the actually criminal acts.
As to the Panthers, they had CI's that initiated criminal activity, that resulted in either the local agency or the feds going in w/ blazing guns.
I'm not making any excuses for the scumbags, but it's important to note the differences between the enforcement actions against white organized subversive scumbags and black organized subversive scumbags.