Due to the great variation in definitions of criminal offenses, standardized definitions were adopted for all offenses to provide nationwide uniformity. Reporting agencies are required to submit data in accordance with these national definitions. Offenses were divided into Index and Non-Index categories. Unfounded complaints are not included in the crime tables. Sub-categories are added for the index offenses of robbery, assault, burglary, and larceny to provide a more detailed look at these offenses.
Agencies also provide statistics on domestic assaults and bias crime.
When reporting incidents where law enforcement officers are killed or assaulted, a separate paper report is required by all law enforcement agencies. Michigan's old UCR program supports various levels of submission ranging from manually processed forms, automated tapes, to on-line data collection. The majority of contributors participate in the incident based system, reporting three-fourths of the state's crime statistics. The remaining agencies report on the summary system. Information submitted through both these systems provides a comprehensive database to define the type and extent of crime in Michigan.