Create Criminal Check

curl --request POST \
  --url https://api.baselayer.com/criminal_checks \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '
{
  "check_type": "instant_criminal",
  "first_name": "John",
  "last_name": "Smith",
  "date_of_birth": "1990-01-15",
  "ssn": "123-45-6789",
  "middle_name": "Mary Louise",
  "phone_number": "+14155552671",
  "primary_address": "123 Main St, Springfield, IL 62704",
  "additional_addresses": [
    "456 Test Blvd, Anytown, GA 44556",
    "456 Oak Ave, Chicago, IL 60601"
  ],
  "reference_id": "Check1234",
  "source_states": [
    "CA",
    "IL"
  ]
}
'

import requests

url = "https://api.baselayer.com/criminal_checks"

payload = {
    "check_type": "instant_criminal",
    "first_name": "John",
    "last_name": "Smith",
    "date_of_birth": "1990-01-15",
    "ssn": "123-45-6789",
    "middle_name": "Mary Louise",
    "phone_number": "+14155552671",
    "primary_address": "123 Main St, Springfield, IL 62704",
    "additional_addresses": ["456 Test Blvd, Anytown, GA 44556", "456 Oak Ave, Chicago, IL 60601"],
    "reference_id": "Check1234",
    "source_states": ["CA", "IL"]
}
headers = {
    "X-API-Key": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {'X-API-Key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    check_type: 'instant_criminal',
    first_name: 'John',
    last_name: 'Smith',
    date_of_birth: '1990-01-15',
    ssn: '123-45-6789',
    middle_name: 'Mary Louise',
    phone_number: '+14155552671',
    primary_address: '123 Main St, Springfield, IL 62704',
    additional_addresses: ['456 Test Blvd, Anytown, GA 44556', '456 Oak Ave, Chicago, IL 60601'],
    reference_id: 'Check1234',
    source_states: ['CA', 'IL']
  })
};

fetch('https://api.baselayer.com/criminal_checks', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.baselayer.com/criminal_checks",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'check_type' => 'instant_criminal',
    'first_name' => 'John',
    'last_name' => 'Smith',
    'date_of_birth' => '1990-01-15',
    'ssn' => '123-45-6789',
    'middle_name' => 'Mary Louise',
    'phone_number' => '+14155552671',
    'primary_address' => '123 Main St, Springfield, IL 62704',
    'additional_addresses' => [
        '456 Test Blvd, Anytown, GA 44556',
        '456 Oak Ave, Chicago, IL 60601'
    ],
    'reference_id' => 'Check1234',
    'source_states' => [
        'CA',
        'IL'
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "X-API-Key: <api-key>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.baselayer.com/criminal_checks"

	payload := strings.NewReader("{\n  \"check_type\": \"instant_criminal\",\n  \"first_name\": \"John\",\n  \"last_name\": \"Smith\",\n  \"date_of_birth\": \"1990-01-15\",\n  \"ssn\": \"123-45-6789\",\n  \"middle_name\": \"Mary Louise\",\n  \"phone_number\": \"+14155552671\",\n  \"primary_address\": \"123 Main St, Springfield, IL 62704\",\n  \"additional_addresses\": [\n    \"456 Test Blvd, Anytown, GA 44556\",\n    \"456 Oak Ave, Chicago, IL 60601\"\n  ],\n  \"reference_id\": \"Check1234\",\n  \"source_states\": [\n    \"CA\",\n    \"IL\"\n  ]\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("X-API-Key", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.baselayer.com/criminal_checks")
  .header("X-API-Key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"check_type\": \"instant_criminal\",\n  \"first_name\": \"John\",\n  \"last_name\": \"Smith\",\n  \"date_of_birth\": \"1990-01-15\",\n  \"ssn\": \"123-45-6789\",\n  \"middle_name\": \"Mary Louise\",\n  \"phone_number\": \"+14155552671\",\n  \"primary_address\": \"123 Main St, Springfield, IL 62704\",\n  \"additional_addresses\": [\n    \"456 Test Blvd, Anytown, GA 44556\",\n    \"456 Oak Ave, Chicago, IL 60601\"\n  ],\n  \"reference_id\": \"Check1234\",\n  \"source_states\": [\n    \"CA\",\n    \"IL\"\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.baselayer.com/criminal_checks")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["X-API-Key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"check_type\": \"instant_criminal\",\n  \"first_name\": \"John\",\n  \"last_name\": \"Smith\",\n  \"date_of_birth\": \"1990-01-15\",\n  \"ssn\": \"123-45-6789\",\n  \"middle_name\": \"Mary Louise\",\n  \"phone_number\": \"+14155552671\",\n  \"primary_address\": \"123 Main St, Springfield, IL 62704\",\n  \"additional_addresses\": [\n    \"456 Test Blvd, Anytown, GA 44556\",\n    \"456 Oak Ave, Chicago, IL 60601\"\n  ],\n  \"reference_id\": \"Check1234\",\n  \"source_states\": [\n    \"CA\",\n    \"IL\"\n  ]\n}"

response = http.request(request)
puts response.read_body

{
  "id": "95853639-eb23-4329-9b92-ddca3eabaaba",
  "created_at": "2026-08-31T10:31:07.766137",
  "first_name": "John",
  "last_name": "Smith",
  "date_of_birth": "1990-01-15",
  "ssn": "XXXXX1234",
  "check_type": "instant_criminal",
  "results": [
    {
      "category": "arrest",
      "person": {
        "addresses": [
          {
            "city": "Anytown",
            "state": "CA",
            "street": "123 Main St",
            "zip": "12345"
          }
        ],
        "date_of_birth": "1990-01-15",
        "date_precision": "FULL",
        "doc_number": "1234567890",
        "ethnicity": "Hispanic-American",
        "eye_color": "HAZ",
        "first_name": "John",
        "gender": "M",
        "hair_color": "BRN",
        "height": "601",
        "last_name": "Smith",
        "middle_name": "Michael",
        "name_aliases": [
          "Mohn Jichael Smith"
        ],
        "race": "W",
        "weight": "180"
      },
      "source": {
        "category": "arrest",
        "name": "KY Franklin County Inmates",
        "county": "Franklin",
        "county_fips_code": "17031",
        "state": "CA"
      },
      "cases": [
        {
          "case_number": "2025-99999",
          "type": "<string>",
          "status": "<string>",
          "file_date": "2025-01-01",
          "file_date_precision": "FULL",
          "arresting_agency": "Franklin County Sheriff",
          "arrest_date": "2025-01-01",
          "arrest_date_precision": "FULL",
          "court_name": "Franklin County Circuit Court",
          "court_county": "Franklin",
          "identity_match_confidence_level": "high",
          "charges": [
            {
              "description": "SHOPLIFTING",
              "offense_date": "2025-01-01",
              "offense_date_precision": "ONLY_YEAR",
              "legal_code": "433.234",
              "type": "felony",
              "category": "Criminal Intent",
              "subcategory": "Accessory",
              "subsubcategory": "SHOPLIFTING",
              "record_date": "2025-01-01",
              "record_date_precision": "ONLY_YEAR",
              "city": "Indian Hills",
              "county": "Jefferson",
              "state": "CA",
              "sentences": [
                {
                  "conviction_date": "2025-01-01",
                  "conviction_date_precision": "FULL",
                  "details": "fine, 1D"
                }
              ],
              "dispositions": [
                {
                  "disposition_type": "Conviction",
                  "disposition": "GLT",
                  "disposition_date": "2025-01-01",
                  "disposition_date_precision": "FULL"
                }
              ]
            }
          ]
        }
      ]
    }
  ],
  "updated_at": "2026-08-31T10:31:07.766150",
  "middle_name": "Mary Louise",
  "phone_number": "+14155552671",
  "email": "john.doe@example.com",
  "primary_address": {
    "city": "Anytown",
    "state": "CA",
    "street": "123 Main St",
    "zip": "12345"
  },
  "additional_addresses": [
    {
      "city": "Anytown",
      "state": "CA",
      "street": "456 Test Blvd",
      "zip": "12345"
    }
  ],
  "reference_id": "Check1234"
}

{
  "detail": [
    {
      "loc": [
        "<string>"
      ],
      "msg": "<string>",
      "type": "<string>",
      "input": "<unknown>",
      "ctx": {}
    }
  ]
}

POST

criminal_checks

Create Criminal Check

curl --request POST \
  --url https://api.baselayer.com/criminal_checks \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '
{
  "check_type": "instant_criminal",
  "first_name": "John",
  "last_name": "Smith",
  "date_of_birth": "1990-01-15",
  "ssn": "123-45-6789",
  "middle_name": "Mary Louise",
  "phone_number": "+14155552671",
  "primary_address": "123 Main St, Springfield, IL 62704",
  "additional_addresses": [
    "456 Test Blvd, Anytown, GA 44556",
    "456 Oak Ave, Chicago, IL 60601"
  ],
  "reference_id": "Check1234",
  "source_states": [
    "CA",
    "IL"
  ]
}
'

import requests

url = "https://api.baselayer.com/criminal_checks"

payload = {
    "check_type": "instant_criminal",
    "first_name": "John",
    "last_name": "Smith",
    "date_of_birth": "1990-01-15",
    "ssn": "123-45-6789",
    "middle_name": "Mary Louise",
    "phone_number": "+14155552671",
    "primary_address": "123 Main St, Springfield, IL 62704",
    "additional_addresses": ["456 Test Blvd, Anytown, GA 44556", "456 Oak Ave, Chicago, IL 60601"],
    "reference_id": "Check1234",
    "source_states": ["CA", "IL"]
}
headers = {
    "X-API-Key": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {'X-API-Key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    check_type: 'instant_criminal',
    first_name: 'John',
    last_name: 'Smith',
    date_of_birth: '1990-01-15',
    ssn: '123-45-6789',
    middle_name: 'Mary Louise',
    phone_number: '+14155552671',
    primary_address: '123 Main St, Springfield, IL 62704',
    additional_addresses: ['456 Test Blvd, Anytown, GA 44556', '456 Oak Ave, Chicago, IL 60601'],
    reference_id: 'Check1234',
    source_states: ['CA', 'IL']
  })
};

fetch('https://api.baselayer.com/criminal_checks', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.baselayer.com/criminal_checks",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'check_type' => 'instant_criminal',
    'first_name' => 'John',
    'last_name' => 'Smith',
    'date_of_birth' => '1990-01-15',
    'ssn' => '123-45-6789',
    'middle_name' => 'Mary Louise',
    'phone_number' => '+14155552671',
    'primary_address' => '123 Main St, Springfield, IL 62704',
    'additional_addresses' => [
        '456 Test Blvd, Anytown, GA 44556',
        '456 Oak Ave, Chicago, IL 60601'
    ],
    'reference_id' => 'Check1234',
    'source_states' => [
        'CA',
        'IL'
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "X-API-Key: <api-key>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.baselayer.com/criminal_checks"

	payload := strings.NewReader("{\n  \"check_type\": \"instant_criminal\",\n  \"first_name\": \"John\",\n  \"last_name\": \"Smith\",\n  \"date_of_birth\": \"1990-01-15\",\n  \"ssn\": \"123-45-6789\",\n  \"middle_name\": \"Mary Louise\",\n  \"phone_number\": \"+14155552671\",\n  \"primary_address\": \"123 Main St, Springfield, IL 62704\",\n  \"additional_addresses\": [\n    \"456 Test Blvd, Anytown, GA 44556\",\n    \"456 Oak Ave, Chicago, IL 60601\"\n  ],\n  \"reference_id\": \"Check1234\",\n  \"source_states\": [\n    \"CA\",\n    \"IL\"\n  ]\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("X-API-Key", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.baselayer.com/criminal_checks")
  .header("X-API-Key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"check_type\": \"instant_criminal\",\n  \"first_name\": \"John\",\n  \"last_name\": \"Smith\",\n  \"date_of_birth\": \"1990-01-15\",\n  \"ssn\": \"123-45-6789\",\n  \"middle_name\": \"Mary Louise\",\n  \"phone_number\": \"+14155552671\",\n  \"primary_address\": \"123 Main St, Springfield, IL 62704\",\n  \"additional_addresses\": [\n    \"456 Test Blvd, Anytown, GA 44556\",\n    \"456 Oak Ave, Chicago, IL 60601\"\n  ],\n  \"reference_id\": \"Check1234\",\n  \"source_states\": [\n    \"CA\",\n    \"IL\"\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.baselayer.com/criminal_checks")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["X-API-Key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"check_type\": \"instant_criminal\",\n  \"first_name\": \"John\",\n  \"last_name\": \"Smith\",\n  \"date_of_birth\": \"1990-01-15\",\n  \"ssn\": \"123-45-6789\",\n  \"middle_name\": \"Mary Louise\",\n  \"phone_number\": \"+14155552671\",\n  \"primary_address\": \"123 Main St, Springfield, IL 62704\",\n  \"additional_addresses\": [\n    \"456 Test Blvd, Anytown, GA 44556\",\n    \"456 Oak Ave, Chicago, IL 60601\"\n  ],\n  \"reference_id\": \"Check1234\",\n  \"source_states\": [\n    \"CA\",\n    \"IL\"\n  ]\n}"

response = http.request(request)
puts response.read_body

{
  "id": "95853639-eb23-4329-9b92-ddca3eabaaba",
  "created_at": "2026-08-31T10:31:07.766137",
  "first_name": "John",
  "last_name": "Smith",
  "date_of_birth": "1990-01-15",
  "ssn": "XXXXX1234",
  "check_type": "instant_criminal",
  "results": [
    {
      "category": "arrest",
      "person": {
        "addresses": [
          {
            "city": "Anytown",
            "state": "CA",
            "street": "123 Main St",
            "zip": "12345"
          }
        ],
        "date_of_birth": "1990-01-15",
        "date_precision": "FULL",
        "doc_number": "1234567890",
        "ethnicity": "Hispanic-American",
        "eye_color": "HAZ",
        "first_name": "John",
        "gender": "M",
        "hair_color": "BRN",
        "height": "601",
        "last_name": "Smith",
        "middle_name": "Michael",
        "name_aliases": [
          "Mohn Jichael Smith"
        ],
        "race": "W",
        "weight": "180"
      },
      "source": {
        "category": "arrest",
        "name": "KY Franklin County Inmates",
        "county": "Franklin",
        "county_fips_code": "17031",
        "state": "CA"
      },
      "cases": [
        {
          "case_number": "2025-99999",
          "type": "<string>",
          "status": "<string>",
          "file_date": "2025-01-01",
          "file_date_precision": "FULL",
          "arresting_agency": "Franklin County Sheriff",
          "arrest_date": "2025-01-01",
          "arrest_date_precision": "FULL",
          "court_name": "Franklin County Circuit Court",
          "court_county": "Franklin",
          "identity_match_confidence_level": "high",
          "charges": [
            {
              "description": "SHOPLIFTING",
              "offense_date": "2025-01-01",
              "offense_date_precision": "ONLY_YEAR",
              "legal_code": "433.234",
              "type": "felony",
              "category": "Criminal Intent",
              "subcategory": "Accessory",
              "subsubcategory": "SHOPLIFTING",
              "record_date": "2025-01-01",
              "record_date_precision": "ONLY_YEAR",
              "city": "Indian Hills",
              "county": "Jefferson",
              "state": "CA",
              "sentences": [
                {
                  "conviction_date": "2025-01-01",
                  "conviction_date_precision": "FULL",
                  "details": "fine, 1D"
                }
              ],
              "dispositions": [
                {
                  "disposition_type": "Conviction",
                  "disposition": "GLT",
                  "disposition_date": "2025-01-01",
                  "disposition_date_precision": "FULL"
                }
              ]
            }
          ]
        }
      ]
    }
  ],
  "updated_at": "2026-08-31T10:31:07.766150",
  "middle_name": "Mary Louise",
  "phone_number": "+14155552671",
  "email": "john.doe@example.com",
  "primary_address": {
    "city": "Anytown",
    "state": "CA",
    "street": "123 Main St",
    "zip": "12345"
  },
  "additional_addresses": [
    {
      "city": "Anytown",
      "state": "CA",
      "street": "456 Test Blvd",
      "zip": "12345"
    }
  ],
  "reference_id": "Check1234"
}

{
  "detail": [
    {
      "loc": [
        "<string>"
      ],
      "msg": "<string>",
      "type": "<string>",
      "input": "<unknown>",
      "ctx": {}
    }
  ]
}

Authorizations

X-API-Key

string

header

required

Body

application/json

Create a criminal check request.

check_type

enum<string>

required

The type of criminal check to run.

Available options:

instant_criminal,

sex_offender_registry

Example:

"instant_criminal"

first_name

string

required

The first name of the person

Minimum string length: 2

Examples:

"John"

"Jane"

last_name

string

required

The last name of the person

Minimum string length: 2

Examples:

"Smith"

"Doe"

date_of_birth

string<date>

required

The date of birth of the person. Cannot be in the future.

Example:

"1990-01-15"

ssn

string

required

The social security number of the person

Required string length: 9 - 11

Pattern: ^\d{3}-?\d{2}-?\d{4}$

Example:

"123-45-6789"

middle_name

string | null

The middle name of the person

Example:

"Mary Louise"

phone_number

string | null

Phone number in E.164 format (US numbers start with +1).

Pattern: ^\+[1-9]\d{1,14}$

Example:

"+14155552671"

primary_address

string | null

The primary address to search for criminal records

Example:

"123 Main St, Springfield, IL 62704"

additional_addresses

string[] | null

A list of additional addresses to search

Example:

[
  "456 Test Blvd, Anytown, GA 44556",
  "456 Oak Ave, Chicago, IL 60601"
]

reference_id

string | null

An optional reference ID to associate with the request. Limited to alphanumeric characters and hyphens.

Maximum string length: 64

Pattern: ^[a-zA-Z0-9_-]{1,64}$

Example:

"Check1234"

source_states

enum<string>[] | null

A list of states criminal records must originate from. When supplied, records are filtered to the specified states only. Records without a source state are always included.

Available options:

AL,

AK,

AZ,

AR,

CA,

CO,

CT,

DE,

DC,

FL,

GA,

HI,

ID,

IL,

IN,

IA,

KS,

KY,

LA,

ME,

MD,

MA,

MI,

MN,

MS,

MO,

MT,

NE,

NV,

NH,

NJ,

NM,

NY,

NC,

ND,

OH,

OK,

OR,

PA,

RI,

SC,

SD,

TN,

TX,

UT,

VT,

VA,

WA,

WV,

WI,

WY,

PR,

VI,

AE,

AA,

AP,

GU,

AS

Example:

["CA", "IL"]

Response

Successful Response

string<uuid>

required

The unique identifier of the criminal check.

Example:

"95853639-eb23-4329-9b92-ddca3eabaaba"

created_at

string<date-time>

required

The date and time when the criminal check was created.

Example:

"2026-08-31T10:31:07.766137"

first_name

string

required

The first name of the person.

Example:

"John"

last_name

string

required

The last name of the person.

Example:

"Smith"

date_of_birth

string<date>

required

The date of birth of the person.

Example:

"1990-01-15"

ssn

string

required

The social security number of the person, masked up to the final four digits

Example:

"XXXXX1234"

check_type

enum<string>

required

The type of criminal check that was run.

Available options:

instant_criminal,

sex_offender_registry

Example:

"instant_criminal"

results

CriminalRecordResponse (v1) · object[]

required

Array of criminal records; empty when none are found.

Show child attributes

updated_at

string<date-time> | null

The date and time when the criminal check was last updated.

Example:

"2026-08-31T10:31:07.766150"

middle_name

string | null

The middle name of the person.

Example:

"Mary Louise"

phone_number

string | null

The phone number of the person in E.164 format.

Example:

"+14155552671"

string | null

The email address of the person.

Example:

"john.doe@example.com"

primary_address

CriminalCheckAddressResponse (v1) · object | null

The primary address of the person.

Show child attributes

Example:

{
  "city": "Anytown",
  "state": "CA",
  "street": "123 Main St",
  "zip": "12345"
}

additional_addresses

CriminalCheckAddressResponse (v1) · object[] | null

A list of additional addresses of the person.

Show child attributes

Example:

[
  {
    "city": "Anytown",
    "state": "CA",
    "street": "456 Test Blvd",
    "zip": "12345"
  }
]

reference_id

string | null

The reference ID associated with this request.

Maximum string length: 64

Example:

"Check1234"

Person

Watchlists & Screening

Criminal Background

Create Criminal Check

Authorizations

Body

Response