Nearly a century of crime data history. Choose a data source to start or read the guide below.
The Crime Data Assistant is an AI-powered research tool that lets you ask questions about crime in the United States using plain English. Instead of downloading spreadsheets or navigating government websites, you type a question like “How have murders trended in Chicago since 2020?” and get back an interactive chart, a data table, and an explanation — all generated in real time.
Under the hood, an AI model translates your question into a database query, runs it against real crime data, and formats the results. Always remember – I am a bot and may make mistakes from time to time. Verify findings with official sources such as the Crime Data Explorer.
Explanation
A plain-English summary of what the data shows, generated by AI with context about limitations.
Chart
An interactive line, bar, or area chart. Hover over data points for exact values.
Data Table
Sortable raw numbers. Click column headers to sort. Export as CSV.
Each database covers different time periods, detail levels, and collection methods. Choosing the right one depends on your question.
| Current Trends | Historical Library | NIBRS Explorer | Homicide Reports | |
|---|---|---|---|---|
| Source | Agency Data Collected by AH Datalytics | FBI Uniform Crime Reports | FBI NIBRS Master Files | FBI Supplementary Homicide Reports |
| Time Range | 2017–present | 1930–2024 | 1991–present | 1976–present |
| Granularity | Monthly Aggregated | Annual Aggregated | Incident-level | Incident-level |
| Coverage | Hundreds of agencies (curated sample) | 10,000+ agencies | Varies by year | Varies by year |
| Crime Types | Part I UCR (7 offenses) | Part I UCR + staffing | 52+ NIBRS offense codes | Homicides only |
| Detail Level | Crime counts + clearance rates | Crime counts + clearance rates + staffing | Demographics, weapons, drugs, property | Victim/offender demographics, weapon, circumstance, relationship |
| Best For | Recent trends, what’s happening now | Long-term trends, historical context | Deep analysis, demographics, specific offenses | Homicide-specific analysis since 1976 |
This data comes from The Crime Index, a project by AH Datalytics that collects monthly crime data directly from police department websites, the FBI's Crime Data Explorer, and public records requests. It covers the 7 traditional Part I UCR crime categories: violent crimes (murder, rape, robbery, and aggravated assault) and property crimes (burglary, theft, and motor vehicle theft). Note that some reported data may be preliminary, subject to change, and may not precisely match figures that will eventually be formally reported to the FBI.
Why it exists: The FBI publishes annual crime estimates with a delay. This dataset fills the gap by providing near real-time monthly data from hundreds of the largest police departments to establish local, statewide, and national crime trends. It's the best source for answering “what's happening right now?”
What “national sample” means: Several hundred agencies report consistently every month. When you ask for “national” trends, the assistant uses only this consistent sample so that month-to-month changes reflect actual crime changes, not agencies dropping in and out of the data.
The Uniform Crime Reporting (UCR) program is the longest-running crime data collection in the U.S., dating back to 1930. The FBI collects annual crime counts from law enforcement agencies nationwide and publishes them as annual reports.
Why it exists: This is the gold standard for historical crime analysis. If you want to know how crime has changed over decades — or compare a city's crime rate in 1990 vs. 2020 — this is the dataset to use.
Key caveat: The data you see here reflects what agencies submitted to the FBI though not all agencies have reported in all years, especially before 1960. Additionally, not every crime is reported to law enforcement every year.
NIBRS is the FBI's modern, incident-level crime reporting system. Instead of just reporting annual totals, agencies submit detailed records for every individual crime incident — including information about victims, offenders, weapons, drugs, property, injuries, and how the case was resolved.
Why it exists: The older Summary Reporting System only captured aggregate offense counts. NIBRS captures a fuller story of each incident. This makes it easy to answer questions like “how many vehicle burglaries were there in Texas last year?” or “what percentage of carjacking victims are male?”
Key caveat: NIBRS participation has grown slowly. In the early 1990s, only a handful of states reported. By 2021, the FBI required all agencies to switch to NIBRS, and coverage is nearly 90% of the U.S. population. When looking at trends over time, always consider whether an increase reflects more crime or simply more agencies reporting. An agency reporting an increase in crimes from one year to the next may have simply started reporting via NIBRS in the middle of a year.
What it can't do: The database has total jurisdiction population but not population broken down by race, gender, or age. This means you can calculate per-capita crime rates for a city or state, but you cannot calculate rates like “murders per 100K females” because the female population isn't available.
The Supplementary Homicide Reports (SHR) are a specialized FBI data collection focused exclusively on homicides. Since 1976, agencies have submitted detailed records for each murder and manslaughter — including victim and offender demographics, weapon used, victim-offender relationship, and the circumstance of the killing.
Why it exists: While NIBRS and UCR count homicides, the SHR provides richer detail about each killing. You can answer questions like “what share of murders involved a firearm?”, “how has domestic homicide trended since 1990?”, or “what is the age breakdown of murder victims in Texas?”
Key caveats: Not all agencies report SHR data every year. Most notably, Florida did not submit SHR data for most years between 1997 and 2020. Alabama and some other states have inconsistent reporting. National counts from SHR will undercount actual homicides.
About offender data: Approximately 40% of homicide incidents have no recorded offender information. Having offender demographics recorded does not mean the case was solved or cleared — this dataset does not measure clearances. When viewing offender breakdowns, results reflect only cases where offender demographics were recorded at the time of reporting.
Example questions you can copy and paste.
“How have murders trended nationally since 2020?”
Uses the national sample to show a rolling monthly trend.
“Compare robbery in Chicago and Houston, 2022 to 2024”
Side-by-side city comparison with a chart.
“Which cities had the highest murder rate per 100K in 2024?”
Ranking query using population-adjusted rates.
“Show me aggravated assault trends in Phoenix over the last 3 years”
Single-city monthly time series.
“What is the national clearance rate for motor vehicle theft by year?”
Uses clearance data to show how often cases are solved.
“What was the murder rate in New York City from 1960 to 2024?”
Long-term single-city trend spanning 60+ years.
“Compare the national murder rate in the 1990s vs. the 2010s”
Decade-level comparison using national aggregates.
“Which cities had the most police officers per capita in 2023?”
Uses staffing data alongside crime counts.
“Show me burglary trends in Los Angeles since 1985”
Tracks one crime type over decades for one city.
“What were the top 10 cities by robbery rate in 2000?”
Historical ranking at a specific point in time.
“What percentage of murder victims in Texas were female in 2023?”
Uses victim demographics data for a single state and year.
“What are the most common weapons used in aggravated assault nationally?”
Breaks down weapon types across all NIBRS-reporting agencies.
“How many carjackings were reported in California from 2019 to 2024?”
Uses the derived carjacking table (robbery + stolen vehicle).
“Show drug offense trends by drug type in Ohio”
Queries the drug summary table for suspected drug breakdowns.
“What is the clearance rate for rape in Florida by year?”
Combines offense counts with arrest/clearance data.
“Compare murder offender demographics in Chicago vs. Houston in 2023”
Uses offender demographics for a cross-city comparison.
“What percentage of murders involved a firearm by year since 1990?”
Long-term weapon trend using SHR's 50-year dataset.
“Break down homicide circumstances in Texas in 2023”
SHR-specific field showing felony vs argument vs other motives.
“What share of homicides are intraracial since 2000?”
Cross-tabulates victim and offender race.
“Show domestic homicide trends nationally since 1990”
Uses relationship_group to isolate family-related killings.
“Victim age and sex breakdown for murders in California in 2022”
Demographic breakdown using victim table.
Crime data is nuanced. Additionally, I am a bot and may sometimes make mistakes. Keep these in mind when interpreting results and always verify findings with official sources if you're uncertain.
Be specific
“Murder rate in Houston 2020–2024” beats “crime in Texas.”
Try different tabs
Each tab draws from a different database. If one can’t answer your question, another might.
Specify a time range
Say “2019 to 2024” instead of “recently” for more relevant results.
Ask follow-ups
The assistant remembers context. Try “now show that as a rate per 100K.”
Built by AH Datalytics. Data is provided as-is for research purposes. Always verify critical findings against the FBI Crime Data Explorer. Not affiliated with or endorsed by the FBI.