art vs business

I take photos of the city I live in as sort of a historical record. In the process I get some cool photos with identifiable people in them. Can I show these at a local photography show?

What about photos of public officials or reporters held on the steps of city hall?

Thanks for your help.

If you cant see their face, then you dont need a model release. If you can, then you do. If your in Canada/USA, not sure about the other countries. But you dont need a release if its for editorial. Im not sure if you do or not for a blog, guess it depends what the blogs purpose is. If its a reportative style about the town, then maybe not, but if its to show off your photography work in the hope you get some business from it, then you probably do.