I have read quite a few press reports on the consequences in New York city following the murder of two officers, notably the apparent "grass roots" mandated non-productivity - mandated by their PBA one assumes:
For the week of 22 December, citywide traffic tickets dropped 94% from the same period in 2013. Court summons for low-level offences, like public intoxication, also dropped 94%. Parking tickets were down 92%. Overall arrests were down 66%, as well.
Even the BBC has done an in-depth report:http://www.bbc.co.uk/news/blogs-echochambers-30659528

A NY Post columnist has a scathing piece, from this distance I assume that paper didn't like the Mayor before:http://nypost.com/2015/01/01/de-blasios-cop-out/