郡 jùn .........canton; county; region
治安 zhì'ān.... law and order; public security
官 ...... guān official; government; organ of body;
When they are taken together they mean what sherif means ~
That 4th character in the group also means Paek in Korean ~ not Park ~ although both names/words are pronounced just about the same in English. A paek was the guy in charge of who got what allocation of land to farm on the large medieval Korean plantations so that'd be more like overseer ~ although one with the authority to just kill a slave
http://www.yellowbridge.com/chinese/chinese-dictionary.php is a good source to figure it all out!
Paek meaning overseer in Korean is funny. The guys who wrote Lost named a ruthless Korean business mogul “Paek”, and they usually hid some kind of reference in people’s names, so that makes sense.