Police prefer the low-hanging fruit. Examples: You and me. It's only rational for cops to arrest old ladies who won't give them any lip for speeding on an otherwise empty highway; it's a whole lot safer for them. Trying to intervene in a crime being committed by a young strong black man is likely to get someone hurt.
I will concede that the murder of two innocent patrolmen was a heinous crime. I will further admit that the grand juries in both Ferguson and New York did their duty as specified by law, and that Al Sharpton et al are a disgrace to the good name of rabble-rousers who have brought a lot of grief to the body politic.
So the police in New York City are withholding their services. They are not "on strike" because striking is illegal. They are showing up for work but not doing anything. They will be out there, neglecting their duties. So, you will no longer have your car towed if you stay overtime in a parking spot--bliss!
There is a downside to this, though. New York will become like San Francisco, a place where the homeless use public fountains as toilets, panhandle aggressively, and menace harmless pedestrians with their threatening demeanor. The squeegee men will be back, offering their unwanted attentions to motorists. This will return the quality of life to the pre-Giulani area, while the New York Times laments the ungovernablity of the city and demands smaller classroom and higher pay for teachers in order to attack the "root causes" of crime. Tourists will flee and businesses will struggle.
I think we need to rethink what we want from policing. Are the police a source of revenue, like bingo games in church meeting rooms? Or are they employed to protect the public?