Methodology

Data Sources

All data on OpenCrime comes from official FBI sources:

FBI Crime Data Explorer (CDE) — Our primary data source for all crime statistics
Summary Reporting System (SRS) — National and state estimated crimes, 1979–2024
Table 8: Offenses Known to Law Enforcement — City-level crime data by state, 2020–2024
CIUS Estimation Tables — FBI's official national crime volume and rate estimates
Expanded Homicide Data — Victim demographics, weapons, circumstances
Hate Crime Statistics — Bias-motivated incidents by state and type

How Crime Rates Are Calculated

Crime rates are expressed as incidents per 100,000 residents. This standardization allows meaningful comparison between cities of different sizes.

Formula: Crime Rate = (Number of Crimes ÷ Population) × 100,000

For example, a city with 500 violent crimes and 200,000 residents has a violent crime rate of 250 per 100,000. Population figures come from the FBI data, which uses Census Bureau estimates.

Crime Categories

Violent Crime (Part I — Violent)

Murder and Nonnegligent Manslaughter — Willful killing of one person by another (excludes justifiable homicide, negligent manslaughter, suicide, accident)
Rape — Penetration without consent (revised definition since 2013)
Robbery — Taking property by force or threat of force
Aggravated Assault — Attack with intent to cause serious bodily injury, often with a weapon

Property Crime (Part I — Property)

Burglary — Unlawful entry of a structure to commit a crime
Larceny-Theft — Unlawful taking of property (shoplifting, pocket-picking, etc.)
Motor Vehicle Theft — Theft or attempted theft of a motor vehicle
Arson — Willful burning of property

Known Limitations

Reporting gap: Not all crimes are reported to police. The Bureau of Justice Statistics estimates only about half of violent crimes are reported.
SRS to NIBRS transition: Between 2017–2020, the FBI transitioned from summary-based to incident-based reporting. This caused a gap in national estimates for those years.
Agency participation: Not all law enforcement agencies submit data every year. City-level data only includes agencies that reported.
Population accuracy: Population figures are estimates and may not reflect seasonal fluctuations, tourism, or commuter populations.
Definition changes: The FBI revised the definition of rape in 2013, making historical comparisons for this category less reliable.
Ranking limitations: The FBI cautions against using crime data to rank or compare communities because crime rates are influenced by many factors beyond law enforcement control.

Data Updates

The FBI typically releases annual crime data in the fall following the reporting year. We update OpenCrime as soon as new data becomes available from the Crime Data Explorer.

Last data update: August 5, 2025 (2024 annual data release)