Frequently Asked Questions

Where does the crime data come from?

The FBI Crime Data Explorer — the national Uniform Crime Reporting program and its NIBRS successor. Population for the per-100,000 rates comes from the U.S. Census Bureau.

Does this measure all crime?

No. It counts offenses reported to police and then submitted by that police agency to the FBI. Unreported crime, and agencies that didn't submit, are not included. A shift in the numbers can reflect reporting changes as much as real change.

What is 'reporting coverage' and why is it on every page?

It's how many law-enforcement agencies covering an area actually submitted data that year. A low crime count can simply mean low coverage, so the rate is meaningless without it. Where coverage is poor we say the figure is unreliable.

Why doesn't every city have a page?

The FBI reports by police agency, not city, and the two don't line up cleanly. If we can't match agencies to a place with enough confidence, or coverage is too low, we don't publish a page for it.

Do you rank the most dangerous cities?

No. We never call a place 'safe' or 'dangerous' and we don't publish 'most dangerous' lists. We report the FBI's figures with their coverage, and let readers draw conclusions.

More detail on sources and limits is on the About the Data page.