Washington Monthly Motor-Vehicle-Theft Offenses, 2018–2025

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

These related tables form this versioned dataset release. Each table has its own downloadable file and field definitions.

Monthly Washington and United States Motor-Vehicle-Theft Series

Principal analysis-ready table containing 96 consecutive monthly observations from the FBI Crime Data Explorer response.

Unit of observation: One calendar month.

View this table

monthly.csv text/csv · 9.9 KB (10,117 bytes)

13 field definitions

Field	Type	Meaning	Units	Value type
month	date	First day of the represented calendar month in ISO 8601 format.	—	observed
wa_reported_offenses	integer	FBI CDE value labeled Washington Offenses for motor-vehicle theft.	reported offenses	observed
wa_offense_rate_per_100k	decimal	FBI-published Washington motor-vehicle-theft offense rate.	reported offenses per 100,000 people	observed
wa_clearances	integer	FBI CDE value labeled Washington Clearances; not synonymous with arrests or cohort resolution.	clearances	observed
wa_clearance_rate_per_100k	decimal	FBI-published Washington clearance rate.	clearances per 100,000 people	observed
wa_population	integer	Washington population value returned by the FBI endpoint.	people	observed
wa_population_coverage_pct	decimal	FBI estimate of the percentage of Washington's population represented by reporting agencies.	percent	estimated
us_reported_offenses	integer	United States reported-offense value returned by the FBI endpoint. The retained response contains zero in this field, so it must not be used as a national count.	reported offenses	observed
us_offense_rate_per_100k	decimal	FBI-published United States motor-vehicle-theft offense rate used as the national descriptive benchmark.	reported offenses per 100,000 people	observed
us_clearances	integer	United States clearance value returned by the endpoint; the retained response contains zero and it must not be treated as a national clearance count.	clearances	observed
us_clearance_rate_per_100k	decimal	FBI-published United States clearance rate.	clearances per 100,000 people	observed
us_population	integer	United States population value returned by the FBI endpoint.	people	observed
us_population_coverage_pct	decimal	FBI estimate of the percentage of the U.S. population represented by reporting agencies.	percent	estimated

Annual Washington Motor-Vehicle-Theft Summary

Yearly sums, changes, clearances, and reporting-coverage ranges derived from the monthly table.

Unit of observation: One calendar year.

View this table

annual-summary.csv text/csv · 809 bytes

10 field definitions

Field	Type	Meaning	Units	Value type
year	integer	Calendar year.	year	derived
months	integer	Number of monthly observations included in the annual row.	months	derived
wa_reported_offenses	integer	Annual sum of Washington reported motor-vehicle-theft offenses.	reported offenses	derived
wa_year_over_year_change_pct	decimal	Percentage change in annual Washington reported offenses from the previous year.	percent	derived
wa_clearances	integer	Annual sum of Washington clearances.	clearances	derived
wa_min_population_coverage_pct	decimal	Minimum Washington population coverage during the calendar year.	percent	derived
wa_max_population_coverage_pct	decimal	Maximum Washington population coverage during the calendar year.	percent	derived
us_reported_offenses	integer	Annual sum of the endpoint's United States offense-count field; all values are zero in this retained response and must not be interpreted as national totals.	reported offenses	derived
us_min_population_coverage_pct	decimal	Minimum U.S. population coverage during the calendar year.	percent	derived
us_max_population_coverage_pct	decimal	Maximum U.S. population coverage during the calendar year.	percent	derived

Washington Pursuit-Law Periods

Exact legal effective dates, descriptions, official source URLs, and transition-month cautions used to define descriptive periods.

Unit of observation: One pursuit-law period.

View this table

policy-periods.csv text/csv · 1.5 KB (1,521 bytes)

7 field definitions

Field	Type	Meaning	Units	Value type
effective_date	date	First date on which the legal period applies.	—	observed
end_date	date	Last date assigned to the legal period within this release.	—	derived
policy_id	string	Stable machine-readable identifier for the policy period.	—	derived
legal_instrument	string	Name and session-law citation of the legal instrument, or baseline label.	—	observed
description	string	Neutral description of the governing pursuit standard.	—	derived
analysis_note	string	Caution relevant to temporal analysis, including transition-month treatment.	—	derived
source_url	uri	Official legal source URL for the period.	—	observed

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.

View this table

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

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.

Saved analyses

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.