README.md

---
license: mit
task_categories:
  - tabular-classification
  - tabular-regression
tags:
  - immigration
  - ice
  - enforcement
  - deportation
  - detention
  - foia
  - duckdb
  - legal
  - policy
  - government-data
pretty_name: ICE Enforcement Database
size_categories:
  - 10M<n<100M
---

# ICE Enforcement Database

A clean, queryable DuckDB database built from ICE enforcement data published by the [Deportation Data Project](https://law.ucla.edu/academics/centers/center-immigration-law-and-policy/deportation-data-project) (Berkeley Law / UCLA) via FOIA litigation.

**22,030,619 rows** across **6 tables** covering ICE arrests, detainers, detentions, removals, and custody decisions.

Combines two FOIA releases:
- **2023 release** (FY2012-FY2023): arrests, detentions, removals, RCA decisions
- **2025 settlement release** (Sep 2023 - Oct 2025): arrests, detainers, detentions

Every row has a `data_source` column (`release_2023` or `release_2025`) so you can filter by release. Overlapping records are deduplicated, preferring the richer 2025 data.

Built with [ice-database](https://github.com/ian-nason/ice-database).

## Quick Start

### DuckDB CLI

```sql
INSTALL httpfs;
LOAD httpfs;
ATTACH 'https://huggingface.co/datasets/Nason/ice-database/resolve/main/ice.duckdb' AS ice (READ_ONLY);

-- Arrests by month
SELECT DATE_TRUNC('month', apprehension_date) AS month, COUNT(*) AS arrests
FROM ice.arrests
WHERE apprehension_date IS NOT NULL
GROUP BY 1 ORDER BY 1 DESC LIMIT 12;
```

### Python

```python
import duckdb
con = duckdb.connect()
con.sql("INSTALL httpfs; LOAD httpfs;")
con.sql(\"\"\"
    ATTACH 'https://huggingface.co/datasets/Nason/ice-database/resolve/main/ice.duckdb'
    AS ice (READ_ONLY)
\"\"\")
con.sql("SELECT * FROM ice._metadata").show()
```

DuckDB uses HTTP range requests, so only the pages needed for your query are downloaded.

## Tables

| Table | Description | Rows | Cols | Sources | Date Range |
|-------|-------------|------|------|---------|------------|
| `detentions` | Detention stays (book-in to book-out) | 9,288,543 | 63 | release_2023, release_2026 | 1995-08-31 to 2026-03-11 |
| `removals` | Deportation/removal records | 3,680,770 | 46 | release_2023, release_2026 | 0212-06-29 to 2023-10-21 |
| `rca_decisions` | Release/custody assessment decision history | 3,543,467 | 42 | release_2023 |  |
| `encounters` | ICE encounters with individuals | 2,586,515 | 24 | release_2026 |  |
| `arrests` | ICE administrative arrests | 2,334,315 | 32 | release_2023, release_2026 | 2011-10-01 to 2026-09-17 |
| `detainers` | Detainer requests issued to jails/prisons | 597,009 | 76 | release_2026 | 1989-09-25 to 2027-01-12 |

## Key Features

### Linked Records
Tables share a `unique_id` field for tracing individuals across the enforcement pipeline: arrests -> detainers -> detentions -> removals.

### Pre-built Views
- `v_arrest_to_detention` - Arrests joined to detention stays
- `v_enforcement_pipeline` - Full pipeline: arrest -> detention -> removal
- `v_daily_arrests` - Daily arrest counts by data source

### Multi-release Deduplication
Where both releases cover the same period, records are deduplicated on key fields (unique_id + date + facility) with the richer 2025 release preferred.

## Data Source

[Deportation Data Project](https://law.ucla.edu/academics/centers/center-immigration-law-and-policy/deportation-data-project) (Berkeley Law / UCLA). Data obtained through FOIA litigation against ICE.

## License

Database build code: MIT. Underlying data: public domain (U.S. government records released via FOIA).

## GitHub

Full source code, build instructions, and example queries: [github.com/ian-nason/ice-database](https://github.com/ian-nason/ice-database)


# Changelog

## 2026-07-06 — Full refresh + data-quality audit

Rebuilt from the Deportation Data Project's 2026 FOIA release (data through
2026-03-10) and repaired after an independent SQL-verified audit.

**Data changes**
- New `encounters` table (2,586,515 rows, release_2026 only).
- Release_2025 fully superseded by release_2026; release_2023 rows inside the
  2026 window (2022-10-01 onward) deleted to prevent double counting.
  Detention supersede keys on *stay* book-out, removing 17,970 previously
  double-counted boundary-spanning segments.
- 12,097 exact-duplicate encounters rows removed.
- Totals: 22,030,619 rows across 6 tables (was 17.8M across 5).

**Fixes**
- Views rewritten: `v_arrest_to_detention` and `v_enforcement_pipeline` now
  produce one row per arrest, matching the first detention stay / removal on
  or after the arrest within the same release (the old versions joined on
  `unique_id` alone, fanning out 3.1x with 20-27% negative durations). New
  `v_detention_stays` view collapses facility segments to stays.
- `removals.departure_date` header rename in the 2026 release handled
  (previously would load as all-NULL).

**Known caveats** (see README for the full list)
- `unique_id` never links across releases (re-anonymized per FOIA release).
- Detainers and encounters exist only from Oct 2022; `rca_decisions` ends
  Sep 2023.
- `arrests` demographics (citizenship, gender, birth year) exist only in
  release_2026 rows.