Public vs. Private Police?

I was going through my grandfather’s police memorabilia after he passed away and I found a patch and a badge that both said private police in English with other words in Latin I believe. Can someone tell me the difference between Public and Private Police?  Are private police just the same thing as security guards except with police powers? What privileges do private police have that’s different from public police or security guards?  Thanks in advance!

Anonymous2020-05-09T15:40:20Z

A good example is an off-duty police officer who "moonlights" as a private detective for a non-governmental agency.

The Oracle of Omigod2020-05-09T15:14:16Z

I do know that some areas hire their own police force and they probably have full policing powers. I am thinking of Indian Village in the center of Detroit. Very rich area.