Unfortunately the rank and file police have little say in the matter. For their administrators, appointed and elected leaders, it's not a matter of toleration, but embrace.
While I have no utopian delusion that crime will ever go away completely, I would also contend that statists have a vested interest in fostering what they deem acceptable levels of it. By handling criminals with kid gloves and setting up revolving door justice, the legal industry guarantees a continued cash stream. Lawyers that graduate to be politicians keep the citizenry at large on edge and fearful, frequently begging for the passage of new, harsh laws rather than simply enforcing existing ones, and this only assists in the consolidation of power. Don't be surprised if the slaying of this cop and the threats against cops results in the call for new gun laws or an attempted watering down of 4th and 5th Amendment rights for organized gangs like the Bloods, the Crips and say, the Tea Party.
Centralized government in fact, needs criminals. When Lenin was making his omelets, you don't really believe he was the one actually breaking the eggs, do you?
And thanks for that...