Re: Is a public school conjoined to a city park not in session considered a public place where one can film?

If you are asking if you have the right to shoot pictures of the public school, ON their property, without permission, then the answer is "NO".

If you are asking if you can shoot a picture of the public school from a public sidewalk across the street, the answer is probably a qualified "YES". There are nuances of the laws on this, with local variations, but as a general concept you are within your rights, so long as any appropriate permits have been issued. As a private individual, rather than a commercial entity, you have somewhat wider rights in this regard. You should google the Photographers Rights card. It can't promise you won't be hassled or even arrested by ill-informed lawmen or witless security guards, but you'll have a better understanding of where you stand from a legal perspective when you decide to push a situation, and it may help you make a cogent argument to whatever self-appointed Jack Baur thinks they have nabbed a terrorist scout or whatever. Though I find that talking to these people is like talking to Vogons. They only listen to their own superiors, not reason. In the modern climate, people are overly cautious about anything to do around schools, they tend to err on the side of ultra-conservatism and reactionary behavior in the light of some vague perceived "threat", and you have to have more than just rights on your side.