57.010.  Election — qualifications — certificate of election — sheriff to hold valid peace officer license, when. — 1.  At the general election to be held in 1948, and at each general election held every four years thereafter, the voters in every county in this state shall elect some suitable person sheriff.  No person shall be eligible for the office of sheriff who has been convicted of a felony.  Such person shall be a resident taxpayer and elector of said county, shall have resided in said county for more than one whole year next before filing for said office and shall be a person capable of efficient law enforcement.  When any person shall be elected sheriff, such person shall enter upon the discharge of the duties of such person's office as chief law enforcement officer of that county on the first day of January next succeeding said election.

  2.  No person shall be eligible for the office of sheriff who does not hold a valid peace officer license pursuant to chapter 590.  Any person filing for the office of sheriff shall have a valid peace officer license at the time of filing for office.  This subsection shall not apply to the sheriff of any county of the first classification with a charter form of government with a population over nine hundred thousand or of any city not within a county.

  3.  The sheriff of any city not within a county shall be required to hold a valid peace officer license pursuant to chapter 590 within two years of being elected as sheriff.