Prepares and tries criminal cases; prepares indictments; conducts pre-trial conferences; negotiates with attorneys; diagnoses cases and determines best case strategies; conducts preliminary hearings; participates in case investigation, including crime scene investigation, interviewing witnesses and victims, and examining evidence; researches legal issues affecting cases; applies the law to facts of a criminal case; determines sentence desired; evaluates and prepares witnesses for trial; selects juries, etc. The purpose of the class is to prepare and prosecute criminal cases in a proper, efficient and orderly manner; to supervise the work of subordinate support staff as assigned, and to perform related professional, administrative and supervisory work as required.