In our area, he Fullerton PD beat a mentally ill homeless man to death, and it was filmed.
Big local outrage, and the Republican DA pressed serious charges against the officers.
In the end, the officers were found not guilty be a jury trial, but several elected and appointed individuals resigned.
These episodes are hard on everybody involved. The police are not fully qualified to deal with mentally ill people.
But they come up short on training, for how to handle people short of killing them, which is what they did on Statten Island and in Fullerton.