Crimes are defined by federal and state law, and in some instances, city ordinances. Within various crimes, there are levels of seriousness, which are commonly called felony, gross misdemeanor, misdemeanor and petty misdemeanor. These levels are generally defined within the state law that defines crime.
Crimes are also commonly placed into two groups
- Crimes Against Persons (such crimes as homicide and rape); and
- Crimes Against Property (burglary and theft).
Crimes are also put into categories of Part I or Part II crimes. These categories are defined by the Federal Bureau of Investigation (FBI). Part I crimes are defined by the FBI as crimes that are generally similarly defined in all 50 states. These Part I crime statistics are commonly used to compare statistics for various communities.
The Police Department keeps statistics for Part I and II crimes. It also keeps records of the various types of service calls to which it routinely responds. Statistics are compiled on a quarterly basis, and include a comparison for the same period for the previous year. The department also compiles statistics on the numbers and types of traffic citations that are issued during the period.
The Department of Justice also puts together a crime clock (PDF), which shows the frequency at which crimes nationally.