Why Is 2021 Crime Data Missing for So Many Cities?

The short answer

From January 2021 the FBI accepted crime reports only through its newer reporting system, called NIBRS. Agencies that had not switched to it could not report that year, so the FBI has little or nothing from them for 2021. In the FBI's data today, 6,950 of the 19,636 police agencies CrimeTally lists had not started NIBRS reporting by 1 January 2021. For every one of them, 2021 is a gap, and CrimeTally shows it as one.

What changed in 2021

For decades most agencies sent the FBI monthly totals: so many robberies, so many burglaries. NIBRS asks for a record of each incident instead, with details about the offense, the victim and the offender. It is a better system, and the Bureau of Justice Statistics describes the change as “a significant improvement in how reported crime is measured.” But switching takes new software, new training and often a new state system in between, and many agencies, including some of the largest, were not ready when the old format stopped being accepted.

What the gap looks like

The New York City Police Department reported 47,959 violent crimes to the FBI for 2020 and 61,293 for 2022. For 2021 the FBI holds twelve monthly entries for the department that add up to a tiny fraction of either year, because the department did not switch to NIBRS until 2023. The FBI left New York out of its own published 2021 city table. CrimeTally marks the year “Incomplete (2021 switch)” and shows no rate.

Whole states were affected. The FBI's participation figures for Florida:

A state figure for a year like Florida's 2021 rests almost entirely on the FBI's estimation method rather than on reports. CrimeTally shows that share beside every year on its state pages.

Why “12 months on file” is not enough

You might expect a missing year to show up as blank. Often it does not. The FBI's data can hold a monthly entry for an agency in 2021 even when that entry holds almost nothing, as with New York. So CrimeTally does not trust twelve monthly entries alone for 2021. It also checks the date the agency began NIBRS reporting, which the FBI publishes for every agency. If that date is after 1 January 2021, the year is marked incomplete no matter what is on file.

What it means for trends

• Treat 2021 as a break, not a dip. A fall in a city's 2021 count is usually missing data, not less crime.
• Years before and after were reported in different systems. The FBI converts NIBRS records into the old monthly totals so the years line up, but a change of system can change what gets counted, so compare across 2021 with care.
• The switch is still finishing. Some agencies started NIBRS in 2022, 2023 or later, and their first NIBRS year can be partial too. The agency page shows how many months each year covers.
• Full years return from 2022. In the FBI's data, many agencies that had not switched show twelve reported months again from 2022 on, so an agency can have a full 2022 and no 2021.

What this guide does not cover

It does not cover how the FBI estimates national or state totals for missing agencies, or the details of what NIBRS records. It also cannot say what crime in a city was in 2021. For agencies that had not switched, nobody can say from this data.

Check your agency

The Crime Rate Lookup shows every year from 2015 for any US police agency in the FBI's data, with the 2021 gap, partial years and non-reporting years each marked in words, and the date the agency began NIBRS reporting.

This guide is for informational purposes only and is not professional advice. A reported crime rate describes what one police agency reported to the FBI. It says nothing certain about any one home, street or school.

Last reviewed: September 2026 · Against the FBI Crime Data Explorer, September 2026 refresh, and the Bureau of Justice Statistics' NIBRS page.