Law enforcement agencies report arrest and offense data either in the Uniform Crime Reporting (UCR) format or the Nebraska Incident-Based Reporting System (NIBRS) format.
Offense data are based upon crimes reported or known to law enforcement. In UCR, offense data are collected on eight crimes:
Homicide is broken down into:
Assault is broken down into
An arrest is counted each time a person is taken into custody or issued a citation or summons. In the case of a juvenile (defined as under the age of 18) an arrest is counted when they are merely warned and released without any further action. While an individual may be charged with multiple crimes at the time of arrest, only one arrest is counted. An arrest is counted for the most serious charge at the time of the arrest.
While law enforcement agencies are required to submit monthly reports, not every agency does. Therefore, the data presented herein may be underreported for some jurisdictions. Please see agencies reporting status for number of months of data provided.
Attempts at comparison of crime figures between jurisdictions should not be made without first considering the individual factors present in each community. Consider factors such as the demographics of the population (racial and ethnic makeup, age and gender, educational levels, prevalent family structures); the industrial/economic base of the jurisdiction; the dependence upon neighboring jurisdictions; dependence upon nonresidents (tourists, conventions, sports activities, etc.); the strength and aggressiveness of a jurisdiction’s law enforcement agency; policies of other components of the criminal justice system (prosecutorial, judicial, correctional, and probational); and the attitudes of the citizens toward crime and their crime reporting practices, especially concerning minor offenses. For more information read the FBI's caution when comparing agencies, Variables Affecting Crime.