Alleged violations of criminal laws are prosecuted by the governmental entity claiming that the violation occurred. Violations of state laws are prosecuted by the County Attorney in the county where the offense occurred. Violations of city ordinances are prosecuted by the city attorney's office. Violations of federal statutes are prosecuted by the United States Attorney’s office in the district where the offense occurred. If the violation is a minor offense not likely to result in your incarceration you are not required to employ an attorney to defend yourself.  If the offense might be result in your incarceration you will be required to employ an attorney and if you cannot afford an attorney one can be appointed to represent to if you meet financial guidelines. I have prepared a guide describing the prosecution and defense of criminal offenses in Iowa.  www.johnmoeller.com