Why are Sheriffs elected in United States?
In other parts of the world the police's chiefs are selected by the city mayor or the city council, but in almost all counties of United States they are elected.
- Why are they elected, and not selected by the mayor?
- Has it always been this way?
It's worth noting that the UK recently moved towards this method: "In the first ever elections, 41 new police and crime commissioners have been elected across England and Wales to give you a say when it comes to cutting crime in your area." (http://www.homeoffice.gov.uk/police/police-crime-commissioners/) - even if it was marred by an extremely low level of turnout!
Although PCCs are not sworn in officers of the law. Their job is in administration (hiring and firing of the chief constable [which is more similar to the role of the sheriff], setting budgets etc.)
Note in some countries, police are not selected at the local level but rather at the state or federal level; and relocated and promoted accordingly.
Also note that sheriffs are not the same as police chiefs and sheriff's departments and police departments play different roles in the US.
A Sheriff in the US is also usually a county or city official, which are traditionally elected. There are exceptions, however, the Sheriff of New York City is directly appointed by the mayor.
The duties of the Sheriff are relatively static, and usually uncoupled from the efforts of appointed law enforcement officials. There's no real reason why a Sheriff would need to be appointed to be more effective in his or her office (in most places), so it remains an elected office allowing for the people to determine if a changing of the guard might be in order.
Depending on the location, the duties of a Sheriff might be almost or completely ceremonial, for which term elections would make sense.