Methodology

Data Source: FBI Uniform Crime Reports (UCR)

CrimeByCounty uses data from the FBI Uniform Crime Reporting (UCR) program, the most comprehensive source of crime statistics in the United States. The UCR program collects data from over 18,000 law enforcement agencies across the country, covering city, county, state, tribal, and federal jurisdictions.

Our current dataset is based on 2022 UCR data, the most recent complete reporting year available. We supplement this with data from County Health Rankings where UCR reporting gaps exist.

The FBI UCR data is publicly available through the Crime Data Explorer.

Crime Metrics

We track two primary categories of crime, each containing specific offense types:

Violent Crime Rate

Violent crime includes offenses that involve force or the threat of force. The violent crime rate is calculated per 100,000 residents and includes:

• Murder and non-negligent manslaughter
• Rape
• Robbery
• Aggravated assault

National average violent crime rate: approximately 380.7 per 100,000.

Property Crime Rate

Property crime includes offenses involving the taking of money or property without force or threat of force. The property crime rate is calculated per 100,000 residents and includes:

• Burglary
• Larceny-theft
• Motor vehicle theft
• Arson (where data is available)

National average property crime rate: approximately 1,954.4 per 100,000.

Total Crime Rate

The total crime rate is the sum of violent and property crime rates per 100,000 residents. The national average total crime rate is approximately 2,335.1 per 100,000.

How Safety Scores Are Calculated

Each county receives a safety score from 0 to 100 using percentile-rank methodology. Here is how it works:

1. Rank all counties: All 3,143 US counties are ranked by their total crime rate (violent + property crime combined).
2. Calculate percentile: Each county's rank is converted to a percentile score. A county with a lower crime rate receives a higher safety score.
3. Normalize to 0-100: Scores are scaled so that 0 represents the least safe county and 100 represents the safest.

A safety score of 85 means the county is safer than 85% of all US counties. A score of 50 represents the national median.

Geographic Coverage

CrimeByCounty covers all 3,143 counties and county-equivalents in the United States, across all 50 states and Washington, D.C. This includes:

• Counties (most states)
• Parishes (Louisiana)
• Boroughs and census areas (Alaska)
• Independent cities (Virginia, Maryland, Missouri, Nevada)

Not all counties have complete FBI UCR reporting. Counties with missing or incomplete crime data receive a default safety score and are clearly labeled. Approximately 85-90% of counties have direct FBI UCR data; the remainder are supplemented with County Health Rankings data where available.

AI-Generated Content Disclosure

CrimeByCounty uses artificial intelligence (Claude by Anthropic) to generate narrative descriptions for state and county pages. These AI-generated narratives summarize and contextualize the underlying data — they do not create or alter the data itself.

All crime rates, safety scores, and statistical figures displayed on this site come directly from government data sources (FBI UCR, County Health Rankings). The AI is used solely to produce readable summaries of this data.

We review AI-generated content for accuracy, but errors may occasionally occur in narrative descriptions. The raw data tables and scores shown on each county page are always the authoritative source.

Data Freshness

Our crime data is updated when new FBI UCR data becomes available, typically on an annual cycle:

• Current data year: 2022 (most recent complete FBI UCR reporting year)
• Update frequency: Annually, when the FBI releases new UCR data
• Safety scores: Recalculated with each data update
• Supplemental data: County Health Rankings (2024 release)

Crime data inherently lags by 1-2 years due to the FBI's collection and verification process. We always display the most recent verified data available.

Limitations

• Reporting gaps: Not all law enforcement agencies report to the FBI UCR program. Some counties may have incomplete data.
• Unreported crime: UCR data only reflects crimes reported to law enforcement. Actual crime rates may be higher.
• County-level aggregation: Crime rates can vary significantly within a county. A county-level rate may not reflect conditions in specific neighborhoods or cities.
• Year-to-year variation: A single year's data may not capture long-term trends. Small counties can show large percentage changes from a small number of incidents.