API Documentation

Unlike competitors with weekly updates, our Sex Offender Registry API features real-time updates, sub-200ms response times, and an exclusive 99.9% Uptime SLA, making it the reliable choice for background checks, security platforms, and public safety applications.

Base URL

Authentication

For quick demos, pass your API key as a query parameter key.

Get a free API key and start with 50 free requests each month.

💡 Using an AI assistant? You can also access full records via our MCP server with the same API key — no code needed.

Request IDs

For production troubleshooting, send an optional X-Request-Id request header with a unique opaque ID from your system. Use a UUID or similar correlation ID; do not include names, email addresses, dates of birth, member IDs, patient IDs, search values, or other sensitive data. Values may contain letters, numbers, ., _, :, and -, up to 64 characters.

The API returns X-Offenders-Request-Id as the Offenders.io-generated request ID on every response. If you send X-Request-Id, the response X-Request-Id echoes your value; otherwise it mirrors the Offenders.io request ID. Include both IDs in support tickets when available. If your client times out before receiving response headers, provide the X-Request-Id you sent plus the exact UTC timestamp.

Search Modes

Regular Search

Targeted lookups by name, DOB, address, zip code, or any combination. Structured address searches use fuzzy address matching by default and are billed at the fuzzy search rate. At least one query param is required.

When a DOB is supplied, Regular Search uses indexed, precision-aware matching: exact records must match the full date, year_month records must match the same year and month, and year records must match the same year. Records with missing or unknown DOB are not included by the Regular indexed DOB path.

Extensive Mode +$0.05/call

Add &mode=extensive to a full-name search to run live source-level enrichment and receive additional jurisdiction data where supported. The standard Extensive request is name-led: send firstName and lastName, then add other supported parameters as filters when needed.

For a structured full-name Extensive search, a supplied DOB is applied to the live name-led candidates using the same precision-aware rules. Candidates with missing or unknown DOB may remain as safety-net matches. Because Extensive Mode uses additional live candidate sources and name variants, it can return a different number of records than the same Regular request; it is not only a response-field enrichment switch.

• aliases — searches all known names and aliases on file
• locations — full address history including residential, employment, and secondary addresses
• stateData — jurisdiction-specific registry details including offenses, vehicles, registration status, and more; field availability varies by jurisdiction

⚠ Slower response (~2s+). Has rate limit — not for batch processing.

GIS / Geospatial Search EXCLUSIVE

Find offenders within a radius of any GPS coordinate. The only API with native geospatial search. Can combine with name/city filters. GIS search includes automatic failover to secondary infrastructure for high availability.

Fuzzy Matching +$0.02/call

Add &fuzzy=true to a name search to enable typo-tolerant matching. Structured address searches are fuzzy by default. Fuzzy matching is generally available, billed at +$0.02 per fuzzy call, and works with or without mode=extensive. It runs on a dedicated search cluster separate from the primary API, providing additional geo-redundancy and infrastructure redundancy. Choose the request shape that matches your input.

Example Matches

These examples illustrate records that may match. Actual results depend on the registry data indexed for each person and any additional filters you send.

Structured Name Search (firstName / lastName)

Best when name fields are separate. fuzzy=true applies to either provided name field, but a structured search requires at least two search parameters overall. For example, send both firstName and lastName, or combine one name with state, zipcode, dob, or GIS coordinates. Each provided name is matched against the correct field for more precise results.

Free-Text Search (q)

Best when you have a single combined name string, or want to search across names and addresses together. Searches across first name, last name, aliases, address, city, and zip code in one query.

Structured Address Search (address)

Best when you have street-address fields separate from names. The address parameter is fuzzy by default, handles common street suffix abbreviations, can be combined with city, state, zipcode, and dob filters, and is billed at the fuzzy search rate. Use either q or address, not both; address also cannot be combined with lat/lng GIS coordinates.

Query Parameters

Response Fields

Each offender object in the offenders array contains:

stateData Schema

The stateData object contains structured, jurisdiction-specific data verified in realtime against authoritative sources where supported. Search coverage includes 183 U.S. registry jurisdictions spanning all 50 states, DC, U.S. territories, and tribal jurisdictions; stateData availability and fields vary by jurisdiction.

Offense Object

Location Object

Field availability varies by jurisdiction. Not all fields are present for every record.

Full Example Response

//Response
{
  "offenders": [
    {
      "name": "First M Last",
      "firstName": "First",
      "firstName_nicknames": ["firsty", "firs", "1st"],
      "lastName": "Last",
      "aliases": [
        {
          "prefix": null,
          "givenName": "FIR",
          "middleName": null,
          "surName": "ST",
          "suffix": null
        },
        {
          "prefix": null,
          "givenName": "FIRST",
          "middleName": "M",
          "surName": "LA",
          "suffix": null
        },
        {
          "prefix": null,
          "givenName": "FIRST",
          "middleName": "NONAME",
          "surName": "LAST",
          "suffix": null
        },
        {
          "prefix": null,
          "givenName": "X",
          "middleName": null,
          "surName": "THE X",
          "suffix": null
        }
      ],
      "dob": "1900-10-01T00:00:00.000Z",
      "dobPrecision": "exact",
      "address": "10000 San Francisco Way",
      "city": "San Francisco",
      "state": "California",
      "zipcode": "94104",
      "locations": [
        {
          "name": null,
          "type": "R",
          "streetAddress": "10000 San Francisco Way",
          "city": "San Francisco",
          "county": "California",
          "state": "CA",
          "zipCode": "94104",
          "zipCodeExtension": null,
          "latitude": 50.12345,
          "longitude": -34.67890
        },
        {
          "name": null,
          "type": "E",
          "streetAddress": "200 FL DRIVE",
          "city": "Miami",
          "county": "Miami-Daide",
          "state": "FL",
          "zipCode": "33129",
          "zipCodeExtension": null,
          "latitude": 34.67890,
          "longitude": -50.12345
        }
      ],
      "sex": "Male",
      "age": "123",
      "offenderUrl": "https://meganslaw.ca.gov/OffenderDisplay.aspx?search...",
      "offenderImageUrl": "https://meganslaw.ca.gov/NSOPWPI.ashx?f=...&NSOPRFlag=True",
      "jurisdiction": "CA",
      "isAbsconder": false,
      "isPredator": true,
      "eyeColor": "Green",
      "hairColor": "Brown",
      "height": "5'11\"",
      "weight": "200 lbs.",
      "race": "White",
      "marks": "tattoo on r_arm (cross / cover the cross with tribal symbol); tattoo on l_arm (pic of a lady); tattoo on l_arm (something); ...",
      "riskLevel": "2",
      "crime": "Crime:  14:81 - Indecent Behavior with Juveniles; Juvenile victim, Conviction date:  2199-09-09, Jurisdiction:  California",
      "registrationDate": "2012-12-31T00:00:00.000Z",
      "content": "<br><b>Zip Code: </b>94104<br><b>Sex: </b>Male<br><b>Age: </b>123...",
      "lat": 50.12345,
      "lng": -34.67890,
      "sources": [
        {
          "name": "National Sex Offender Public Website",
          "id": "nsopw",
          "url": "https://www.nsopw.gov/"
        },
        {
          "name": "New York State Division of Criminal Justice Services",
          "id": "criminaljustice.ny.gov",
          "url": "https://www.criminaljustice.ny.gov/"
        }
      ],
      "updatedAt": "2026-03-05T21:35:42.936Z",
      "uuid": "5893a310-37ce-58d8-b101-39e76a60e94a",
      "stateData": {
        "stateOffenderId": "SO-123456",
        "status": "Active",
        "designation": "Sexually Violent Offender",
        "offenses": [
          {
            "offense": "AGGRAVATED SEXUAL BATTERY",
            "convictionDate": "11/04/1999",
            "statute": "18.2-67.3",
            "jurisdiction": "Richmond Circuit",
            "victimAge": "Unknown"
          }
        ],
        "aliases": ["JOHN A DOE", "JOHNNY DOE"],
        "initialRegistrationDate": "2000-12-19",
        "lastVerificationDate": "2026-02-20",
        "judgmentOfConvictionUrl": "https://sexoffenders.ehawaii.gov/coveredoffender/resource/A3005425__QA.pdf",
        "complianceStatus": "COMPLIANT",
        "isLifetimeRegistration": true,
        "incarcerationStatus": "On Parole",
        "lawAgency": "RICHMOND POLICE DEPT",
        "vehicles": [{"plate":"ABC1234","make":"Toyota","year":"2015"}],
        "victimInfo": [{"gender":"Female","minor":true}]
      }
    }
  ]
}

Result Limits

• Regular Search: 50 records max. Filter by city or zip for better results.
• GIS Search: Radius defaults to 1 mi (max 100 mi). 50 records per page — use page and totalPages to paginate. Each page request counts as one billable API call. By default, GIS results are limited to records updated within the last 90 days. Use updatedAtStart to override this window.
• Fuzzy Search: Up to 500 records per request. Requires at least two search parameters for structured name search.

Error Handling

When the error field is present in the response, results may be incomplete or empty. Your application should check for this field and handle accordingly.

Code Examples

JavaScript / Node.js

const res = await fetch(
  `https://api.offenders.io/sexoffender?key=${API_KEY}&zipcode=94104`
)
const { offenders } = await res.json()
console.log(offenders[0].name, offenders[0].city)

Python

import requests

r = requests.get("https://api.offenders.io/sexoffender", params={
    "key": API_KEY,
    "firstName": "Alice",
    "zipcode": "94104"
})
offenders = r.json()["offenders"]

cURL

curl "https://api.offenders.io/sexoffender?key=YOUR_KEY&lat=30.967&lng=-91.116&radius=2"

cURL (POST with Header Auth)

Use X-API-Key, or swap that header for Authorization: Bearer YOUR_KEY.

curl -X POST "https://api.offenders.io/sexoffender" \
  -H "Content-Type: application/json" \
  -H "X-API-Key: YOUR_KEY" \
  -H "X-Request-Id: 550e8400-e29b-41d4-a716-446655440000" \
  --data '{"firstName":"Alice","lastName":"Smith","fuzzy":true}'

# Bearer token form also works:
# -H "Authorization: Bearer YOUR_KEY"

Batch Processing

Need to process thousands of records? Use our web-based batch tool at batch.offenders.io — upload a CSV with First Name, Last Name, and optional DOB. See the Batch Processing Guide for details.