About the Data

The Transactional Records Access Clearinghouse (TRAC) has drawn upon a variety of data sources, combining the records we received as result of our FOIA requests and other efforts with approximately 3.4 million records obtained by Human Rights Watch through its independent FOIA request. Most of the data are drawn from the Department of Homeland Security's ENFORCE tracking system. (This information was formerly part of Immigration and Custom Enforcement's Deportable Alien Control System or DACS.) The data, organized by detention facility, include specific information on the date an individual was booked into a facility, the date the individual was booked out of that facility, a code for the reason he or she left the facility, and information on gender and nationality. For additional information see Background to this Research.

Records analyzed in these reports cover the period from October 1, 1998 through March 31, 2008. According to the government, these records cover the detention history of each individual who passed through ICE detention facilities or facilities of its predecessor agency, the Immigration and Naturalization Service (INS), during this period.

References to the "last 12 months" are for the period April 1, 2007 through March 31, 2008. A facility was included in the rankings if it had at least 10 transfers during this period. (Because of the absence of any translation for the facility code, no report was prepared on one facility included in the rankings.)

In calculating the annual average number of transfers over the decade for a facility, the average is rounded to the nearest whole number. (For facilities with 1-4 transfers, the average was rounded up to 1.)

ICE now claims it is operating the largest detention system in the country. Of course ICE has no authority to hold anyone for criminal violations of any law. Rather, these persons were held by ICE because of questions regarding their immigration status. Detention usually occurs while ICE is awaiting authorization to deport the individual or during the deportation process itself.

ICE uses many different types of detention facilities. These fall into the following general categories:

ICE Service Processing Center (SPC). An ICE owned detention facility used to house individuals who have been detained by ICE because of questions about their immigration status. SPCs were formerly owned and operated by ICE. Now, however, SPCs are owned by ICE but operated by private sector companies. The SPCs are among several different types of facilities commonly used by ICE to house detainees.

Contract Detention Facility (CDF). A detention facility owned and operated by a private company in the business of providing detention services under a government contract. Like the SPCs the CDFs are one of several types of facilities used by ICE to house detained individuals.

Intergovernmental Service Agreement (IGSA) Facility. IGSAs are agreements between the federal government and a state or local government to provide detention beds in jails, prisons, and other local or state government detention facilities. While government owned, these facilities may be operated by either local or state agencies or by a private company in the business of providing detention services. Some of these facilities may even be dedicated for federal use.

Federal Bureau of Prisons (BOP) Facility. A federal prison typically used to house individuals convicted of a federal crime during the term of their prison sentence. However, ICE sometimes uses BOP facilities to house individuals not convicted of any crime but in ICE custody and detained because of questions regarding their immigration status.

Holding/Staging Facility. A secure area where ICE detainees may be temporarily held, often co-located in ICE field offices and subfield offices. ICE detention standards allow individuals to be held in a holding area for up to 12 hours, and in a staging facility for up to 16 hours. These facilities do not provide sleeping quarters or shower facilities.

Juvenile Facility. Special facilities designated for the housing of juveniles while they are being detained because of questions regarding their immigration status. These are often operated by religious, charitable or nonprofit organizations. Detention in these facilities may be administered directly by ICE or be handled by the Office of Refugee Resettlement.[1]

Other Facility. Facilities not falling into any of the above categories. Typically these are motels, hotels, hospitals or other medical facilities.

[1] The Office of Refugee Resettlement is an agency within the Department of Health and Human Services that assists in refugee resettlement of immigrants in this country. This agency under immigration law also has the responsibility for providing housing and other services to unaccompanied juveniles under 18 years of age who have been detained by ICE because of questions regarding their immigration status.