GA allows for the county government to merge with one or more of the municipalities within it. These are called consolidated governments.
The neighboring county to me consolidated in 1991 or 1992. That county had an existing county PD. The city PD and the county PD merged. When I went to the academy in 1999, that agency was still struggling from the merger and issue still popup from time to time. It's only faded from being an issue as the old heads are now steadily retiring.