Improving the 911 EMS system won't improve police response time in Oakland because Oakland, like most of the US, has an ongoing shortage of police officers. There isn't any easy way to make the job of a police officer more attractive.
The recent fury directed at the handful of police officers who did not enter this or that school with an active shooter comes to mind. People have the expectation that police officers are required to die for us. Imagine being told by someone who already hates you, that you are supposed to die for them.
It feels like we are awfully entitled when it comes to the police. We expect them to serve us with the highest integrity, kindness, & selflessness, while offering them mediocre pay, disgust, & hatred in exchange.
The body cam of that man in the hotel corridor being just one of the latest.
I can't say I blame would-be "good cop" cadets deciding not to join the force to be associated with these acts; the willingness to protect bad cops by leadership seems, from the outside, to mean the entire system is rotten and impossible to change from within.
The reason "the narrative" exists, I think, is that there's a widespread perception that regardless of the circumstances of the shooting -- even if the evidence clearly shows the police shot an unarmed victim in the back multiple times, for instance -- the police tend to get off on the grounds that they "felt threatened." This contributes to a feeling that the police are held to a lesser standard than non-police suspects, rather than the same standard.
People in minority communities around the U.S. have said for generations that the police abused them; I give that some serious credibility. Also, there is much more to abuse than killings; there are many reports on widespread abuses by police departments, such as Baltimore and New Orleans.
I will add that in at least some other countries police do their job and shoot hardly anyone; I think in Scotland it's on the order of one per decade.
If any of the people in this thread wish to have a go at that, try here: http://www.killedbypolice.net/kbp2018
Pick a year, note how many police shootings are listed there for that year, then generate 20 random numbers in the range [1, N] where N is the number of said shootings, and look at the corresponding killings. That should give some reasonable insights.