FBI Crime Data Analysis

Mapping participation gaps in U.S. crime reporting

Trusting Koala
Yuqing Sun(ys2434), Maria Chang (mc2995), Tianyi Wang (tw324)

2026-03-05

Introduction

Law enforcement agencies across the U.S. vary widely in how they report crime. Not all agencies participate in NIBRS, and not all joined at the same time.

Who is missing from the data, and when did agencies finally show up?

Q1: Are certain agency types systematically less likely to participate?

Even within the same state, patterns emerge: State Police and catch-all agency types consistently fall below their state’s baseline, while Tribal and County agencies tend to exceed it.

Participation is partly a state story

Western states cluster near 100% adoption. Pennsylvania and Florida notably lag.

The gaps hold across the country

Negative gaps for State Police and “Other” reappear in FL, NJ, and NY. CA and IL show smaller, less consistent patterns.

Q2: When did agencies adopt NIBRS?

City and County agencies adopted steadily over decades. Tribal and University agencies surged only after the 2021 federal mandate.

Where did adoption happen last?

Virginia and Michigan adopted early. California, New York, and Florida only moved after the 2021 deadline.

Thanks for your attention!