U.S. Immigration and Customs Enforcement (ICE) detains certain noncitizens in removal proceedings. This Key Homeland Security Indicator (KHSM) includes initial book-ins to and book-outs (final releases) from ICE detention.
As some terminology in reports do change, we maintain previously posted reports and datasets as originally approved and published.
Note: We round data to the nearest 10.
Source: OHSS Statistical System of Record based on data received from ICE.
Data Source
All Detentions KHSM data are from the OHSS Statistical System of Record (SSOR). The SSOR is the authoritative source of DHS statistical data and undergoes rigorous validation. We construct SSOR data for this dataset from ICE provided administrative records stored in the Enforcement Integrated Database (EID).
Data Lineage
ICE extracts book-in and book-outs data from EID using the ICE Integrated Decision Support (IIDS) System Data Mart (DSSDM) reporting system. ICE uploads the data to the CBP Unified Immigration Portal (UIP) monthly. We download the data as a comma-separated values (CSV) file and produce detention data in the SSOR.
Units of Measure and Descriptive Variables
Units of Measure
Book-in
A physical book-in to a detention facility. Multiple book-ins can occur within a detention stay. This KHSM is limited to initial book-ins. It excludes book-ins resulting from transfers among detention facilities.
Book-out
A physical book-out or release from a detention facility. Multiple book-outs can occur within a detention stay. This KHSM is limited to final release book-outs. It excludes releases resulting from transfers among detention facilities.
People who have more than one initial book-in or final release book-out during the reporting period are counted multiple times in the tables.
Descriptive Variables
Arrest Location
The location of the apprehension or arrest of an individual resulting in the detention stay:
- Border: Latest apprehension or arrest was by United States Border Patrol (USBP) or Office of Field Operations (OFO). We report noncitizens arrested by USBP or OFO and processed by ICE as Border arrests.
- Interior: Latest apprehension or arrest was by ICE. Includes referrals from United States Citizenship and Immigration Services (USCIS) as well as noncitizens arrested at the border, subsequently released, and then re-arrested by ICE.
Country of Citizenship
A country to which a person owes allegiance and by which they are entitled to be protected. Each country sets its own rules for granting citizenship. These rules may be based on birth or naturalization. Some people may not have a country of citizenship.
Criminality (2-Category)
A Yes/No variable that describes whether an individual was convicted of a criminal offense before.
Release Reason
- Removal Book-out: A noncitizen is released from custody to be removed from the United States to their country of origin. Includes noncitizens ordered removed by an Immigration Judge (IJ), granted voluntary departure by the IJ or the agency, requested to voluntarily return, who withdrew their application for admission, and Title 42 expulsions.
- Order of Supervision: A noncitizen has a final order of removal with no appeals pending with the Board of Immigration Appeals (BIA) and is released from custody subject to reasonable conditions pursuant to INA section 241(a)(3) of the Immigration and Nationality Act (INA).
- Bonded Out: A noncitizen is released from custody on Bond subject to conditions pursuant to section 236(a) of the INA. These are primarily issued to release a noncitizen who has been placed in removal proceedings before an IJ. Also includes Bonds approved by the agency.
- Order of Recognizance: A noncitizen is in removal proceedings after being issued a Notice to Appear (NTA) or has an appeal pending with the BIA and is released from custody subject to reasonable conditions pursuant to section 236(a) of the INA.
- Paroled: An arriving noncitizen is released from custody on Parole subject to reasonable conditions pursuant to section 212(d)(5) of the INA.
- Relief: A noncitizen is released from custody upon being granted relief from removal by an IJ. Includes Cancellation of Removal, Asylum, or Adjustment of Status forms of relief.
- Other: Includes book-outs upon termination of removal proceedings by an IJ; transfers to a federal, state, local, or tribal law enforcement agency; death; escape; runaways from the Office of Refugee Resettlement; and retired release codes that are no longer in the ICE Systems of Records. A small number of cases in the other category are those with updates made to the case in the system of record. Others are cases are ICE transfers. These are cases where a subject is released from an ICE facility to be transferred to another facility pending book-in, when the subject was not booked back in within 72 hours. The latter two book-out types don't have a change in custody status or a physical release from custody.
ICE ERO Areas of Responsibility (AORs)
ICE Enforcement and Removal Operations (ERO) has 25 field offices. These are geographic areas of responsibility around the country. A field office director heads each field office. The field office is authorized to plan and conduct immigration enforcement and removal operations.
List of AORs: Atlanta, Baltimore, Buffalo, Burlington, Centennial, Chantilly, Chicago, Dallas, Detroit, El Paso, Fort Snelling, Harlingen, Houston, Los Angeles, New Orleans, New York, Newark, Philadelphia, Phoenix, Plantation, San Antonio, San Diego, San Francisco, Seattle, West Valley City.
Data Processing
ICE provides us with the book-in and book-out data for this KHSM. Book-in data includes details of all noncitizens with an ICE initial book-in to detention for a stay within a given time period. Book-out data includes where the individual is released from custody and the final release book-out reasons.
We clean and de-duplicate ICE book-in and book-out data. We define the descriptive variables of this KHSM using values found within each observation within the respective event's data.
Data Cleaning
- Strip time values from dates in date fields.
- Strip special characters from the data columns.
- Delete extra blank columns or rows.
- Compare new data files with the previous quarters to see if there is any unexplained increase or drop in the total count.
Integration
A single data source is used to produce the Detentions KHSM.
Imputation
We don’t substitute any missing data for the Detentions KHSM.
Limitations
Undercount and Overcount
We don't count transfers between ICE facilities as a new detention event. As such, transferred noncitizens may be booked into an ICE facility without triggering a new detention event. We record every eligible detention event in the Enforcement Integrated Database (EID) to ensure complete coverage. To ensure consistency between the counts in our reports and the data publicly released by ICE, we only remove administrative records ICE directs us to. We do not de-duplicate these records.
Accuracy
We extract data from live systems that are subject to change. Statistical information is subject to change due to corrections, systems changes, changes in data definition or adding information.
Previous months’ reporting may change during the same fiscal year as records mature and due to operational data quality efforts. We permanently lock data at the end of the fiscal year as part of the September monthly lock-down. Our encounter reporting always uses the most recent monthly updated data.
We round each row of data to the nearest 10 to protect privacy and security. As a result, the actual totals and the totals of the rounded rows can vary.
Timeliness
We update this KHSM on a 45-day delay following the end of the month to allow time for operational data quality checks and other data maturity efforts before release. We update this KHSM on the third Thursday of each month. Data are current as of the report date and update previous releases.
Linkage Error
There is currently no linkage of data for this KHSM report.
Reporting Period
Book-in data are available from 2010 to present. Book-out data are available from 2013 to present.
Changes from Previous Releases
In the December 2024 report, FY 2013-2014 Detentions Book-outs only included Releases, which includes Order of Supervision, Bonded Out, Order of Recognizance, Paroled, and Relief. In the January 2025 report we now include Removal Book-outs and additional Book-outs in the ‘Other’ category, such as termination of removal proceedings by an Immigration Judge.
In the December 2024 report, Arrest Location defaulted to ‘Interior’ for all Detentions Book-outs in FY2013-2014 due to an error in the data processing. In the January 2025 report FY 2013-2014 data for Detentions Book-outs Arrest Location are corrected and now consistent with 2015-Present.
Related Data and Information
OHSS reports:
