Alien Incarceration Report 

Fiscal Year 2017, Quarter 4 

December 21, 2017
1

On January 25, 2017, the President signed Executive Order (EO) 13768 on Enhancing Public 

Safety in the Interior of the United States. 

Section 16 of the EO directs the U.S. Department of Homeland Security (DHS) and the 

Department of Justice (DOJ) to collect relevant data and provide quarterly reports on: (a) the 

immigration status of all aliens incarcerated under the supervision of the Federal Bureau of 

Prisons (BOP); (b) the immigration status of all aliens incarcerated as federal pretrial detainees 

under the supervision of the United States Marshals Service (USMS); and (c) the immigration 

status of all convicted aliens incarcerated in state prisons and local detention centers throughout 

the United States. 

This Fiscal Year (FY) 2017, Quarter 4 report includes data on aliens incarcerated under the 

supervision of BOP and USMS.

Summary of Findings 

A total of 58,766 known or suspected aliens were in in DOJ custody at the end of FY 2017, 

including 39,455 persons in BOP custody and 19,311 in USMS custody. 

Of this total, 37,557 people had been confirmed by U.S. Immigration and Customs Enforcement 

(ICE) to be aliens (i.e., non-citizens and non-nationals), while 21,209 foreign-born people were 

still under investigation by ICE to determine alienage.

Among the 37,557 confirmed aliens, 35,334 people (94 percent) were unlawfully present. These 

numbers include a 92 percent unlawful rate among 24,476 confirmed aliens in BOP custody and 

a 97 percent unlawful rate among 13,081 confirmed aliens in USMS custody. 

This report does not include data on the foreign-born or alien populations in state prisons and 

local jails because state and local facilities do not routinely provide DHS or DOJ with 

comprehensive information about their inmates and detainees. This limitation is noteworthy 

because state and local facilities account for approximately 90 percent of the total U.S. 

incarcerated population. DHS and DOJ are working to develop a reliable methodology for 

estimating the status of state and local incarcerated populations in future reports. 

ICE-DOJ Immigration Status Determinations 

Pursuant to EO 13768, USMS and BOP facilities have begun providing to ICE on a quarterly 

basis comprehensive biographic data on inmates and detainees who are identified as foreignborn. In turn, ICE checks USMS and BOP foreign-born detainee data against its ICE 

Enforcement and Removal Operations (ERO) case management system, the ENFORCE Alien 

Removal Module (EARM), and the U.S. Citizenship and Immigration Services’ Central Index 

System to identify aliens with immigration records and pending or completed removal 

proceedings. This approach allows ICE to place each foreign-born person within one of the 

following five categories for each quarterly report: 
2

• Under Investigation: Further investigation by ICE is required to confirm alienage and

establish potential removability.

• In proceedings – Legal: Confirmed alien who is lawfully present in the United States but

has been charged as a removable alien; removal proceedings are ongoing.

• In proceedings – Illegal: Confirmed alien who is unlawfully present1

in the United States

and has been charged as a removable alien; removal proceedings are ongoing.

• Subject to final order of removal: Confirmed alien who is subject to a final order of

removal—meaning that the alien has no lawful status in the United States.

• Relief/Benefit: Confirmed alien who has been granted relief or protection from removal 

that would generally be considered lawful status. However, depending on the nature of

the inmate’s criminal offense, his/her status may be subject to review and rescission or

revocation by DHS or an immigration judge. 

Immigration Status of Aliens in BOP Custody

As of September 28, 2017, a total of 24,476 confirmed aliens were housed in BOP facilities, and 

an additional 14,979 foreign-born individuals in BOP facilities remained under ICE 

investigation; together these known and suspected aliens accounted for 21 percent of all federal 

inmates in BOP custody.2 At least 22,614 aliens in BOP facilities were unlawfully present, 

including 20,240 people (51 percent of the total) who had been ordered removed and 2,374 

people (six percent) who were unlawfully present and in removal proceedings. Less than five 

percent of the total (1,852 people) were lawfully present and in removal proceedings, and just 10 

aliens had received an immigration benefit or received relief from removal. See Figure 1. 

Under the Institutional Hearing and Removal Program, ICE and BOP are working to complete 

immigration court proceedings prior to the completion of an alien’s sentence in order to reduce 

or eliminate the need for further detention once an alien is released to ICE custody from BOP. 

As a result, ICE and BOP expect the proportion of the foreign-born population remaining in the 

“under investigation” status to decline over time—a trend that was observed in this quarter. As 

of September 28, 2017, 38 percent of foreign-born inmates were under investigation, down from 

50 percent on June 24, 2017. While persons under ICE investigation represented a smaller 

percent of the known and suspected alien population, the percentage who had been ordered 

removed increased from 44 percent of the total in Q3 to 51 percent in Q4. 

1 The immigrations laws define “unlawful presence” to include those circumstances where an “alien is present in the 

United States after the expiration of the period of stay authorized ... or is present in the United States without being 

admitted or paroled.” 8 U.S.C. § 1182 (a)(9)(B)(ii). Unlawfully present includes those who entered the United 

States without being admitted or paroled, and may include those who subsequently adjusted status or were lawfully 

admitted but the Immigration Court System has issued an administrative final order rendering them unlawfully 

present. 

2

 Total counts in BOP and USMS facilities reflect the populations on reported dates and are not quarterly or yearly 

totals. 
3

Figure 1: Known and Suspected Aliens in Bureau of Prisons Custody, September 28, 2017. 

 Source: U.S. Department of Homeland Security. 

Immigration Status of Aliens in USMS Custody 

The USMS is DOJ’s component charged with the housing and care of federal pretrial detainees. 

USMS also houses certain short-term sentenced aliens, as well as sentenced aliens pending 

transfer to the BOP; this report includes data on all known and suspected aliens in USMS 

custody.3 As of October 2, 2017, a total of 19,311 known and suspected aliens were housed in 

USMS facilities Of the confirmed aliens in USMS custody, 66 percent (12,720) were unlawfully 

present, including 11,459 aliens (59 percent) with an administrative final order of removal and 

1,261 aliens (6.5 percent) who were unlawfully present but pending adjudication in removal 

proceedings. See Figure 2.

Most of the remainder (6,230 individuals or 32 percent) were still under investigation. Less than 

two percent of confirmed aliens in USMS custody who have been screened by ICE were lawfully 

present and in immigration proceedings (358 individuals). As of October 2, 2017, USMS was 

housing only three aliens in receipt of a grant of protection or relief. 

3

 USMS data reflects all aliens in USMS custody. No distinction was made to delineate solely pre-trial aliens as the 

USMS also detains post-trial aliens completing short term sentences and/or transfer to USBOP. 

Under 

Investigation, 

14,979

Under Adj (Legal), 

Under Adj (Illegal), 1,852

2,374

Ordered Removed, 

20,240

Pending 

Relief/Benefit, 10
4

Figure 2: Known and Suspected Aliens in U.S. Marshals Service Custody, October 2, 2017 

Source: U.S. Department of Homeland Security. 

Ordered Removed, 

11,459

Pending 

Relief/Benefit, 3

Under 

Investigation, 6,230

Under Adj (Legal), 

358

Under Adj (Illegal), 

1,261