Method
How we built the DC data
Everything on the DC data page comes from two free public sources. One script, pipeline/pull.mjs, pulls both and writes a single data file, and the site is built from that file. No number on the page is typed in by hand.
Housing: Census American Community Survey
US Census Bureau, ACS 5-year estimates for 2020-2024 (release 2024), from api.census.gov. The Census publishes DC's eight wards as the District's "state legislative districts (upper chamber)", so each ward's numbers come straight from that geography, not from ZIP codes stitched together.
- Renters: B25003_003 over B25003_001.
- In buildings of 10 or more units: B25024 cells 007 to 009 over B25024_001. Rowhouses: B25024_003 (one unit, attached). Detached: B25024_002.
- Moved in 2020 or later: B25038 owner and renter households whose householder moved in 2020 to 2022 or 2023 and later (cells 003, 004, 010, 011), over occupied units.
- No vehicle: B25044 cells 003 and 010 over occupied units.
- Median year built: B25035_001.
Limits: these are survey estimates averaged over five years, with margins of error. The wards were redrawn in 2022, and the Census labels these as the 2024 ward lines.
Crime: Metropolitan Police Department incidents
DC publishes every crime incident MPD reports, one map layer per year, on DC Open Data (the FEEDS/MPD service on maps2.dcgis.dc.gov). We ask that service for counts, grouped by offense, for 2015 through 2025, and for 2023, 2024, 2025 also by ward. We use three offenses: BURGLARY, MOTOR VEHICLE THEFT and THEFT F/AUTO (theft from a vehicle). 2025 is the most recent complete year. Counts are incidents as reported and can be revised; they are not arrests or convictions. Ward counts before 2023 are left out because the ward lines changed in 2022.
Refresh
Running the pull script again rebuilds the data file and compares a hash of it with the last one. This page's date moves only when the numbers change. New ACS releases arrive each December, and the current year's MPD layer fills in as the year goes on.
Cite this
Four Quadrant Keys, "DC lock and key data by ward," https://fourquadrantkeys.com/dc-lock-and-key-data/, data as of October 28, 2026. Sources: US Census Bureau ACS 2020-2024; DC Metropolitan Police Department crime incidents via DC Open Data.