Descriptive Statistics by Washington Pursuit-Law Period

What this dataset measures

Washington's pursuit-law debate repeatedly cites changes in vehicle theft, but annual headlines obscure timing, reporting coverage, and differences among official measures. This release preserves the underlying FBI response, exposes a reproducible monthly series, joins exact legal effective dates, and publishes validation and limitations so temporal associations can be examined without presenting them as causal effects.

Geography

Washington State, United States

Unit of observation

One calendar month for the principal Washington and United States series; one calendar year or one legal-policy period in derived tables.

Update cadence

Immutable research release; refreshes require a new version because FBI historical values may be revised.

Curator

FactHub Research Team

Curated data tables

Descriptive Statistics by Washington Pursuit-Law Period

Unadjusted averages for complete calendar months assigned to each legal period, with transition months excluded.

Unit of observation: One pursuit-law analysis period.

policy-period-descriptives.csv text/csv · 615 bytes

All 4 rows 10 columns Download the file

All 4 rows

period	start_month	end_month	months months	mean_monthly_wa_offenses reported offenses per month	mean_wa_rate_per_100k reported offenses per 100,000 people per month	mean_us_rate_per_100k reported offenses per 100,000 people per month	mean_wa_to_us_rate_ratio ratio	minimum_wa_population_coverage_pct percent	causal_interpretation_permitted
pre_hb1054	2018-01-01	2021-06-01	42	2251.9	29.65	19.24	1.58	99.25	False
hb1054_full_months	2021-08-01	2023-04-01	21	4070.8	52.74	23.68	2.23	98.94	False
sb5352_full_months	2023-06-01	2024-05-01	12	4034.9	51.75	25.87	1.99	99.03	False
i2113_full_months	2024-07-01	2025-12-01	18	1996.3	25.42	18.03	1.4	95.65	False

10 field definitions

Field	Type	Meaning	Units	Value type
period	string	Stable identifier for the legal-analysis period.	—	derived
start_month	date	First complete calendar month included in the period.	—	derived
end_month	date	Last complete calendar month included in the period.	—	derived
months	integer	Number of complete monthly observations included.	months	derived
mean_monthly_wa_offenses	decimal	Arithmetic mean of monthly Washington reported offenses.	reported offenses per month	derived
mean_wa_rate_per_100k	decimal	Arithmetic mean of the FBI-published monthly Washington offense rate.	reported offenses per 100,000 people per month	derived
mean_us_rate_per_100k	decimal	Arithmetic mean of the FBI-published monthly U.S. offense rate.	reported offenses per 100,000 people per month	derived
mean_wa_to_us_rate_ratio	decimal	Mean of the monthly ratio between Washington and U.S. offense rates.	ratio	derived
minimum_wa_population_coverage_pct	decimal	Lowest Washington population-coverage estimate among included months.	percent	derived
causal_interpretation_permitted	boolean	Explicit safeguard indicating whether the descriptive row may be presented as a causal estimate; always false.	—	derived

Supporting files

Source snapshots, manifests, quality reports, documentation, and other materials used to produce or review this release.

• fbi-cde-wa-mvt-2018-2025.json Source · application/json · 19.2 KB (19,634 bytes)

  Immutable FBI Crime Data Explorer API response retained as the source snapshot for this release.

• README.md Documentation · text/markdown · 8.4 KB (8,633 bytes)

  Dataset purpose, source selection, article use, file guide, build instructions, and acquisition priorities.

• quality-report.md Quality report · text/markdown · 5.1 KB (5,177 bytes)

  Definitions, automated checks, reporting coverage, conflicting official values, limitations, and publication cautions.

• source-audit.md Documentation · text/markdown · 7.9 KB (8,085 bytes)

  Audit of official public sources, their suitability, discrepancies, and the source hierarchy used for this release.

• release-manifest.json Source manifest · application/json · 3 KB (3,046 bytes)

  Release metadata and SHA-256 digests for the original research artifacts.

• build.ps1 Transformation manifest · text/x-powershell · 9.8 KB (10,008 bytes)

  Executable acquisition, transformation, validation, summary, and digest-generation recipe.

Sources

1. Federal Bureau of Investigation Crime Data Explorer Principal source for monthly Washington and United States offenses, clearances, rates, population, and population-coverage values.

   Retrieved October 7, 2026. U.S. federal government data. Retained source response is redistributed for reproducibility with attribution to the FBI Crime Data Explorer.

2. Washington State Legislature Official source for HB 1054 and its 2021 pursuit-law effective date.

   Retrieved October 7, 2026. Washington State public record. Linked as an official public record; source document bytes are not redistributed in this release.

3. Washington State Legislature Official session law for SB 5352 and its immediate May 3, 2023 effective date.

   Retrieved October 7, 2026. Washington State public record. Linked as an official public record; source document bytes are not redistributed in this release.

4. Washington State Legislature Official session law for Initiative 2113 and its June 6, 2024 effective date.

   Retrieved October 7, 2026. Washington State public record. Linked as an official public record; source document bytes are not redistributed in this release.

Limitations and reproducibility

Fully reproducible from the retained FBI API response with Windows PowerShell 5.1 or newer and no additional packages.: The public release includes the immutable source response, transformation and validation script, generated tables, release manifest with SHA-256 digests, source audit, quality report, and build instructions. Running scripts/build.ps1 without -Refresh rebuilds from the retained response; -Refresh intentionally acquires potentially revised source values and therefore requires a new release.

• The principal series is a statewide aggregate and cannot identify which agencies or counties drove a change.
• Reported offenses are not necessarily unique stolen vehicles, victims, suspects, arrests, recoveries, or pursuits.
• The release contains no vehicle make or model and cannot directly measure the Kia and Hyundai theft wave.
• The release does not measure attempted theft, failures to yield, or incidents in which officers did not initiate a pursuit.
• The release does not contain police staffing, deployment, prosecution, detention, or task-force activity.
• FBI source values can be revised after this immutable release.
• Washington population coverage declines to approximately 95.7%–96.1% in the second half of 2025.
• The United States series is a descriptive benchmark, not a causal counterfactual for Washington.
• All three pursuit-law changes occurred during a month; the descriptive period table excludes those transition months.
• FBI offense totals do not reconcile with separately published WACIC and WATPA stolen-vehicle figures; the measures must not be treated as interchangeable.
• Policy-period averages are unadjusted, highly confounded descriptions and must not be described as causal effects.