The city of Elkhorn has released the findings of a months-long investigation into Fire Chief Trent Eichmann, concluding there is "substantial evidence that Chief Trent Eichmann violated the city's personnel policies, code of ethics, and his fire chief oath of office."The city hired an outside law firm to investigate allegations against Eichmann. The law firm interviewed several Elkhorn Fire Department employees, including Eichmann.According to t…