Methodology

Data sources

Agency data is compiled from the following sources:

• ICE 287(g) participants list — the current official list of participating agencies published at ice.gov. Scraped and archived regularly.
• appelson/Tracking_287g — a community archiving effort that maintains historical ICE spreadsheets and individual MOA PDFs going back to 2016.
• FBI Census of State and Local Law Enforcement Agencies (CSLLEA) 2018 — population served, budget, officer counts, and contact information.

Matching agencies

Agency names vary across sources. We normalize names and use fuzzy string matching to link records across datasets, then hand-review ambiguous matches. Each agency in our index includes a confidence score for its cross-source matches.

Limitations

• Population data is from 2018 CSLLEA and has not been updated. It reflects jurisdiction size, not the population directly affected by 287(g) enforcement.
• Some agencies have had agreements lapse and rejoin. Historical participation dates may be incomplete.
• MOA PDFs are not available for all agencies. We link to the appelson archive where available.

Updates

The pipeline is re-run regularly to capture new ICE announcements. The data snapshot date is shown on each page.