Since Charlotte NC has experience such amazing growth in the past 20 years, the city has expanded to the size of the county almost. There are several towns outside of Charlotte, but inside of Mecklenburg county. Many departments of city and county government have merged to provide better services to these communities and the county as a whole.
The Charlotte Mecklenburg Police Department is one of the department. I really don't know all the ins and outs of the policing in Charlotte. But there are Mecklenburg county Sheriffs. I have no idea what they do though. If the city and county police are the same thing, then where do the county sheriffs patrol?
Maybe they just take care of the county jail or something. You really don't see many sheriff's cars around in Charlotte.
The schools are another department that has seen a merger between county and city. It really has been that way for a long time. I can't remember when the city schools weren't part of the county system. Their pooled resources probably caused a stir when they merged, but it may have made the city and county schools better as a result. Or it may have caused problems, who knows.