I’m looking for something non-nationality-specific to visually represent police and policing. Everything I can find, however, and everything I can think of myself, is based on imagery specific to one nation’s police force (mostly USA or UK).
I did, however, find a quote from the book Visual Information For Everyday Use which sums up my problem neatly:
…the ISO [tried] to develop a symbol to indicate ‘police’ by using a hat worn by police. The problem was that the hat varies throughout the world and not everybody can be expected to be familiar with the hats worn by police in different countries.
I thought there must be some kind of international standard used in signposting, map making, etc, but I can’t find one.
For the context I need it, it needs to be non-negative, so not hand-cuffs or anything else off-putting (the context is about going to the police for help).
I’ve got a feeling there’s some standard symbol similar to this (example from Noun Project, Rflor), but I can’t find any information about what the original is or what its provenance is.
For some reason I associate this image with the police in Italy, not sure why.
Here’s a link to a quick discussion on international symbology you might find interesting since you’ve already read about the ISO standard.
A Brief History of International Symbols
As the article and @johannes mentioned in the comments to your question, there is the American Institute of Graphic Arts (AIGA) 50 icon set designed in 1974 that has become a free to use international icon set. Unfortunately there is no police icon.
A more recent standardization of international symbology has been undertaken buy the United Nations and the OCHA.
The OCHA is the part of the United Nations Secretariat responsible for bringing together humanitarian actors to ensure a coherent response to emergencies.
You were on the right path with the Noun Project icons you were already looking at.