Interesting on this point.
One of the clients that I manage, the cops came to their house. They asked the resident to allow the cops to setup security video cameras in my client's back yard. The client's back yard faced the back yard on the next street over of a suspect of a crime (not sure if drugs or something else). The cops came in and installed all their own video equipment to point at this other house to monitor them 24/7, from my client's property, NOT from a public location.
So, this is like your scenario of someone turning over security footage from their own cameras, only taking it one step further because the cops installed security cameras on private property (with permission of course... but what did they DO get get that permission, I don't know)