What does the Uniform Crime Reports that the FBI publishes are based on information taken from?

The Uniform Crime Reports (UCR) published by the FBI are based on data collected from law enforcement agencies across the United States. These agencies voluntarily report crimes that occur in their jurisdictions, including statistics on offenses such as murder, robbery, and aggravated assault. The UCR aims to provide a comprehensive overview of crime trends and patterns at the national, state, and local levels. Data is typically reported on a monthly basis, contributing to an annual summary of crime statistics.