I'm not sure what you mean "private police" - the Boston night watch, which predated the 1838 professional police force, were given powers by the town government[1]. I can't find any references to how the night watch was funded, but surely the town government was involved.
Edit:
> The duties of the Watch, as appears by the order, were to be performed in turn by the inhabitants; they were not "citizen soldiers," but citizen Watchmen, and having an interest in their work, no doubt did it well.
- A chronological history of the Boston watch and police
by Savage, Edward H.[2]
Savage seems to indicate that the night watch was performed in turn by the inhabitants of the community, by order of the government, and there is no mention they were paid. This doesn't seem like a private service to me.
Edit:
> The duties of the Watch, as appears by the order, were to be performed in turn by the inhabitants; they were not "citizen soldiers," but citizen Watchmen, and having an interest in their work, no doubt did it well.
- A chronological history of the Boston watch and police by Savage, Edward H.[2]
Savage seems to indicate that the night watch was performed in turn by the inhabitants of the community, by order of the government, and there is no mention they were paid. This doesn't seem like a private service to me.
1. https://en.wikipedia.org/wiki/Boston_Watch
2. https://archive.org/details/achronologicalh01savagoog/page/n...