The only place that isn't a foreign version of Mayberry RFD that really has unarmed police (At least the beat officers are unarmed) is metropolitan England, where it works (Mostly) only because -
1. There is a pervasive government surveillance system, not just miscellaneous business security cams, in the high crime areas that they police;
2. The society, despite and influx of Muslims good and bad since the independence of the Subcontinent occurred mid-20th Century, is still rather homogeneous, especially as compared to ours;
3. There are laws against privately-owned weapons and self-defense (In anything but an utter back-to-the-wall, no-possible-escape situation) that are so Draconian that the penalties are worse than what the perps get for robbery with anything but firearms themselves, and sentences are much lighter than in the US for anything but firearms crime so there is far less incentive for the perps to arm themselves.
4. There are a shitload of cops compared to most US metro areas, and armed police are immediately available for backup if the perps prove to be armed.
I don't think you DUmmies would be on board for the whole package, and without the first and last of them, the third one would be a disaster, while the second is a fundamental demographic difference that government can't change.
However, I am all for a trial run, pulling all cops (And Conservatives) out of a couple of sample Liberal-infested areas, banning civilian guns there, forbidding government video surveillance in those zones, and having a 'No hard time' policy for mere grand theft, assault, or strong-arm robbery until around the third offense, then just 18 months to a year. Should go just great, but we'll need to run it about five years to see how it plays out.
