Congress might consider reforms to the nation's immigration system, and, thus, the detention of noncitizens (aliens) in the United States may be an issue. Congressional interest in the policy of detaining noncitizens in the United States while determining whether noncitizens should be removed from the United States tends to be varied. For example, while some want to increase the categories of aliens who are detained and increase the amount of detention space, others want to create alternatives to detention and exempt asylum seekers from mandatory detention. In addition, immigration enforcement activities affect the need for and allocation of detention resources. For example, as the Department of Homeland Security (DHS) expands programs to locate removable aliens from jails throughout the country, DHS may need additional detention beds in areas of the United States where traditionally there has not been a need for detention space. The Immigration and Nationality Act (INA) provides broad authority to detain aliens while awaiting a determination of whether they should be removed from the United States and mandates that certain categories of aliens are subject to mandatory detention (i.e., the aliens must be detained) by DHS. Aliens not subject to mandatory detention may be detained, paroled, or released on bond. Any alien can be detained while DHS determines whether the alien should be removed from the United States. Approximately half of the detained aliens have committed a crime while in the United States, have served their criminal sentence, and are detained while undergoing deportation proceedings. Other detained aliens include those who are arrested in the United States for being illegally present, or who arrived at a port-of-entry without proper documentation (e.g., fraudulent or invalid visas, or no documentation), but most of these aliens are quickly returned to their country of origin through a process known as expedited removal. The majority of aliens arriving without proper documentation who claim asylum are held until their "credible fear hearing," but some asylum seekers are held until their asylum claims have been adjudicated. This report provides an overview of immigration detention in the United States. It begins with a discussion of the authority to detain noncitizens while awaiting a determination of whether the noncitizen is removable from the United States. The report continues with a discussion of the resources for immigration detention and concludes with a discussion of legislation in the 112 th Congress related to detention. The report also presents general policy issues surrounding detention of aliens, including concerns about the number of aliens subject to mandatory detention; the justness of mandatory detention, especially as it is applied to asylum seekers arriving without proper documentation; and the proper limits on the length of time in detention for aliens who have been ordered removed but cannot be returned to their home country. The daily responsibility for detaining aliens resides with the Secretary of Homeland Security, but under law the Attorney General may still retain the authority to arrest and detain aliens. The INA provides the Attorney General with broad authority to detain aliens while awaiting a determination of whether they should be removed from the United States. The creation of DHS moved the administration of detention of noncitizens from the Department of Justice's Immigration and Naturalization Service (INS) to DHS. While current regulations vest all authorities and functions of the DHS to administer and enforce the immigration laws with the Secretary of Homeland Security (hereafter the Secretary) or his delegate, it can be argued that the language in the Homeland Security Act of 2002 (HSA) has left the Attorney General with concurrent authority over some aspects of immigration law. In addition, both the Department of Justice, through the Executive Office of Immigration Review (EOIR), and DHS have authority for determining bond for aliens. Officials within DHS also make bond determinations that may or may not subsequently come before EOIR. The Board of Immigration Appeals (BIA), the appellate body within EOIR, hears appeals from matters decided by immigration judges. The BIA has jurisdiction to consider appeals of various decisions made by immigration officials in DHS, including the granting of bond. The Attorney General has final say in matters of immigration law that come before EOIR. For example, on April 17, 2003, the Attorney General released a decision that instructs immigration judges to consider "national security interests implicated by the encouragement of further unlawful mass migrations" in making bond determinations for unauthorized migrants who arrive in "the United States by sea seeking to evade inspection." In the decision, the Attorney General states that he retains the authority to detain or authorize bond for aliens, but the authority is "shared" with the Secretary since DHS's officials make the initial determination whether an alien will remain in custody during removal proceedings. As discussed above, the INA gives the Attorney General the authority to issue a warrant to arrest and detain any alien in the United States while awaiting a determination of whether the alien should be removed from the United States. The Illegal Immigrant Reform and Immigrant Responsibility Act of 1996 (IIRIRA) amended the INA, effectively specifying levels of detention priority and classes of aliens subjected to mandatory detention. Mandatory detention is required for certain criminal and terrorist aliens who are removable, pending a final decision on whether the alien is to be removed. No bail is available and only a hearing can determine whether the alien qualifies as a criminal or terrorist alien. Aliens not subjected to mandatory detention can be paroled, released on bond, or continue to be detained. Decisions on parole made by the Secretary and bond decisions made by the Attorney General are not subject to review. In October 1998, the former INS issued a memorandum, which is still in effect, establishing detention guidelines consistent with the changes made by IIRIRA. According to the guidelines, detainees are assigned to one of four detention categories: (1) required; (2) high priority; (3) medium priority; and (4) lower priority. Aliens in required detention must be detained (e.g., criminal aliens, national security risks) while aliens in the other categories may be detained depending on detention space and the facts of the case. Higher priority aliens should be detained before aliens of lower priority. Additionally, INA Section 236A requires the detention of an alien whom the Attorney General certifies as someone who the Attorney General has "reasonable grounds" to believe is involved in terrorist activities or in any other activity that endangers national security. The Attorney General must initiate removal proceedings or bring criminal charges within seven days of arresting the alien or release the alien. An alien who is detained solely as a certified terrorist, who has not been removed, and who is unlikely to be removed in the foreseeable future may be detained for periods of up to six months only if his release would pose a danger to national security or public safety. The Attorney General must review the terrorist certification every six months. Under the INA, the Attorney General also has the authority to arrest and detain aliens without a warrant if he has "reason to believe that the alien ... is in the United States in violation of any [immigration] law and is likely to escape before a warrant can be obtained." Functionally, DHS is responsible for arresting and detaining aliens. If an alien is arrested without a warrant, a decision must be made within 48 hours to detain or release the alien. Aliens paroled or released on bond may be rearrested at any time. Additionally, after a removal order has been issued against an alien, the law provides that the alien subject to a final removal order be removed within 90 days, except as otherwise provided in the statute. Certain aliens subject to a removal order "may be detained beyond the removal period and, if released, shall be subject to [certain] terms of supervision." This provision had been interpreted as permitting indefinite detention where removal was not reasonably foreseeable, but in 2001, the U.S. Supreme Court in Zadvydas v. Davis , interpreted it as only permitting detention for up to six months where removal was not reasonably foreseeable. The INA contains both criminal and civil violations. Historically, the authority for state and local law enforcement officials to enforce immigration law has been construed to be limited to the criminal provisions of the INA. The enforcement of the civil provisions, which includes apprehension and removal of deportable aliens, has strictly been viewed as a federal responsibility, with states playing an incidental supporting role. Although there is debate with respect to state and local law enforcement officers' authority to enforce civil immigration law, it is permissible for state and local law enforcement officers to inquire into the status of an immigrant during the course of their normal duties in enforcing state and local law. For example, when state or local officers question the immigration status of someone they have detained for a state or local violation, they may contact a DHS Immigration and Customs Enforcement (ICE) agent at the Law Enforcement Support Center (LESC). The federal agent may then place a detainer on the suspect, requesting the state official to keep the suspect in custody until a determination can be made as to the suspect's immigration status. However, the continued detention of such a suspect beyond the needs of local law enforcement, and solely designed to aid in enforcement of federal immigration laws, may be unlawful. The law requires the detention of criminal aliens; national security risks; asylum seekers, without proper documentation, until they can demonstrate a "credible fear of persecution"; arriving aliens subject to expedited removal (see the section entitled, "Expedited Removal and Detention"); arriving aliens who appear inadmissible for other than document related reasons; and persons under final orders of removal who have committed aggravated felonies, are terrorist aliens, or have been illegally present in the country. In addition, Section 236 of the INA provides for the mandatory pre-removal-order detention of an alien who is certified by the Attorney General as a terrorist suspect. Thus, it can be argued that the Attorney General and the Secretary of DHS have the discretion to detain any alien who is in removal proceedings, and must detain all aliens who are charged as terrorists, and almost all aliens charged as criminals upon their release from criminal incarceration whether they are released on probation or parole. Prior to 2001, the mandatory detention provisions created in IIRIRA had led to some aliens being in indefinite administrative custody (i.e., civil detention or immigration detention). These aliens had been ordered removed from the United States, but were detained because the aliens could not obtain travel documents to another country or the immigration officials refused to release them. These detainees were often referred to as "lifers" or "unremovables." Many of these detainees had criminal records, but some simply lacked immigration status and the ability to return to their country of origin. Some detainees had been in immigration detention for a longer time period than their criminal incarceration. In 2000, which was the final year before the Supreme Court ruling limiting the time in detention for aliens who had been ordered removed, INS estimated that it had 5,000 aliens in indefinite administrative custody. In a 5-4 decision in Zadvydas v. Davis (2001), the U.S. Supreme Court held that a statute permitting indefinite detention would raise serious constitutional problems because the Due Process Clause of the Fifth Amendment prohibits depriving any person, including aliens, of liberty without due process of law. Therefore, in keeping with principles of statutory construction and the absence of clear congressional intent for indefinite detention, the Court read an implicit limitation into the post-removal detention statute, such that detention is limited to a period "reasonably necessary" to achieve an alien's removal. The Supreme Court established six months after the removal order as the presumptively reasonable period within which to effect removal. After this period, once an alien shows that there is good reason to believe that "there is no significant likelihood of removal in the reasonably foreseeable future," the government must rebut that showing with sufficient evidence. The Court emphasized that its holding does not mean that all aliens must be released in six months nor that an alien may not be held until it has been determined that "there is no significant likelihood of removal in the reasonably foreseeable future." The Court suggested that special arguments could be made for a statutory scheme of preventive detention for terrorists or other aliens in special circumstances and for heightened judicial deference for executive and legislative branch decisions regarding national security matters. In response to this decision, the Attorney General issued regulations governing the review of post-removal order detention cases for a determination of foreseeability of removal. The Attorney General issued regulations, effective November 14, 2001, concerning the continued detention of aliens subject to final orders of removal that are consistent with the Zadvydas decision. Subsequently, then Chief Immigration Judge Michael Creppy issued a memorandum on the Immigration Court's policy regarding these regulations. The regulations and the memorandum establish four categories of aliens whose removal from the United States is not foreseeable, but whom the Attorney General may continue to detain. These "special circumstances" include aliens with a highly contagious disease that poses a threat to public safety; aliens whose release would cause serious adverse foreign policy consequences; aliens detained for security or terrorism reasons; and aliens determined to be specifically dangerous. Of these four categories, only the fourth requires the involvement of the Immigration Court; the other three remain under DHS discretion. In Clark v. Martinez , the Court held that the rationale it applied in Zadvydas to aliens who had been admitted to the United States and were deportable also applied to aliens who had not been legally admitted into the United States, were found inadmissible and ordered removed, and were being detained beyond the statutory removal period although removal was not reasonably foreseeable. Accordingly, the six-month presumptive detention period applied. In Zadvydas , the Court explicitly let stand an older decision which distinguished between the indefinite detention of an excludable alien (similar to inadmissible alien under current law) who sought to enter the United States and a deportable alien who had entered the United States. Therefore, the Court had suggested that it might reach a different conclusion for indefinite detention of inadmissible aliens from the one it reached in Zadvydas for deportable aliens and noted that the statutory purposes and constitutional concerns for deportable aliens were not the same for inadmissible aliens. However, in Clark v. Martinez , it decided that to treat inadmissible aliens differently under the removal statute would render an inconsistent interpretation of the removal statute, where the statute itself made no distinction between the treatment of inadmissible and deportable aliens. Justice Thomas criticized the Court's opinion as departing from its constitutional rationale in Zadvydas and its suggestion in that case that inadmissible aliens presented a different situation. At the same time, Justice Thomas agreed with the Court's "fidelity to the text" of the removal statute; he believed that Zadvydas had been wrongly decided and should have been overruled. Aliens who arrive in the United States without valid documentation or with false documentation are subject to a process known as "expedited removal," under which the alien is ordered removed from the United States, and the removal decision is not subject to any further hearings, reviews, or appeals. Most aliens subject to this process face continuous detention. Aliens subject to expedited removal must be detained until they are removed and may only be released due to medical emergency or if necessary for law enforcement purposes. If the arriving alien expresses a fear of persecution or an intent to apply for asylum, the alien is placed in detention until a "credible fear" interview can be held. If the alien is found to have a credible fear, he may be paroled into the United States. If the credible fear is unsubstantiated, the alien is detained until the alien is removed from the United States. As discussed earlier, the Illegal Immigrant Reform and Immigrant Responsibility Act of 1996 (IIRIRA) mandated that aliens who arrive without proper documentation and claim asylum be detained prior to their "credible fear" hearing. Prior to IIRIRA, most aliens arriving without proper documentation who applied for asylum were released on their own recognizance into the United States (and given work authorization), a practice which enabled inadmissable aliens falsely claiming persecution to enter into the country. Most of the fraudulent claims were made by people attempting to come to the United States for economic or family reasons, illegally rather than through legal immigration channels. False asylum claims utilize limited resources, causing those with legitimate claims to have to wait longer to have their cases processed. Thus, many argued that the only way to deter fraudulent asylum claims was to detain asylum seekers rather than releasing them on their own recognizance. Indeed some claim that the practice of detaining asylum seekers has reportedly helped reduced the number of fraudulent asylum claims. However, some contend that the policy of detaining all asylum seekers is too harsh. They argue that there is a need to inhibit fraudulent asylum claims, but mandatory detention of asylum seekers causes more problems than it solves. The position of the United Nations High Commission for Refugees is that detention of asylum seekers is "inherently undesirable." Detention may be psychologically damaging to an already fragile population such as those who are escaping from imprisonment and torture in their countries. Often the asylum seeker does not understand why they are being detained. Additionally, asylum seekers are sometimes detained with criminal aliens. Some contend that DHS should develop alternatives to detention (e.g., electronic monitoring) for asylum seekers. The Secretary has the authority to parole detained aliens who are not subject to mandatory detention. Most arriving aliens are not eligible for parole. Parole is permitted for arriving aliens with serious medical conditions, pregnant women, juvenile aliens who will be witnesses, and "aliens whose continued detention is not in the public interest." In general, parole is available on a "case-by-case basis for urgent humanitarian reasons or significant public benefit." Aliens not subject to mandatory detention may also be released on bonds of a minimum of $1,500. To be released on bond, the alien must prove that he is not a threat to people or property, and will appear at all future immigration proceedings. The courts have ruled that detained aliens not under expedited removal have the following rights: the right to apply for asylum; the right to communicate with consular or diplomatic officers of their home country; the right to be represented by counsel (but not at government expense); the right to challenge transfers to other detention facilities that might interfere with the right to counsel; the right to medically adequate treatment; the right to access free legal service lists and telephones; and the right to self-help and other legal reference material. Under the law, aliens also have the right to legally challenge their detention. Custody and bond determinations can be reviewed by an immigration judge at any time before the removal order becomes final, except in certain cases. Additionally, the alien may appeal the immigration judges' decision to the Board of Immigration Appeals. Nonetheless, the courts have afforded the Administration much discretion in decisions related to where aliens are detained, the management of detention facilities, and the treatment of aliens. Although there is consensus that detainees should be treated humanely, there is no consensus on exactly what the conditions of detention should be. In 2000, the former Immigration and Naturalization Service created National Detention Standards for aliens in detention, which are published in the Detention Operations Manual. In late 2008, ICE published new Detention Standards in a performance-based format, and these standards were revised in 2011. The standards, known as Performance-Based National Detention Standards 2011 (PBNDS 2011) specify the detention conditions appropriate for immigration detainees. In many cases, the standards mirror American Correctional Association standards, though some of ICE's Detention Standards provide more specificity or are unique to the needs of alien detainees. The Detention Standards, however, do not have the force of law, thus detainees do not have legal recourse for violations of the standards. Some argue that immigration detention, which is civil detention, is unlike criminal incarceration. They contend that despite the differences, the public views immigration detention as identical to criminal incarceration, and that the government wrongly manages both confined populations in the same way. They also note that number and type of detention facilities make it difficult for ICE to ensure that the national detention standards are being followed. In 2009, the Obama Administration created the Office of Detention Policy and Planning (ODPP) in ICE with the goal of overhauling the current immigration detention system and "designing a detention system that meets the unique needs of ICE's detained population." According to their website: "ODPP will shape the future design, location and standards for civil immigration detention facilities so that ICE no longer relies primarily on existing penal models." Nonetheless, others contend that detained noncitizens should not receive better treatment than U.S. citizens who are arrested and awaiting trial, noting that aliens are in detention because they have violated U.S. law. As Figure 1 shows, from FY2002 to FY2013, the average size of the daily noncitizen detention population increased by almost 75%, from 19,922 in FY2002 to 34,696 in FY2013. During the same time period, the number of funded beds increased from 19,702 to 34,000. The largest increase in the average daily detention population occurred between FY2006 and FY2007, when Congress increased bed space funding from 20,800 to 27,500 beds. In addition, except for two years, between FY2002 and FY2007, the number of funded beds was less than the average daily detention population. Between FY2008 and FY2011, the number of funded beds exceeded the average daily detention population. Conversely, in FY2012 and in the first quarter of FY2013, the daily detention population has exceeded bed space funding. Nonetheless for obvious reasons, the average daily detention population is closely tied to the amount of funded bed space. ICE detained an all-time high of approximately 429,000 foreign nationals during FY2011. During that year, the average daily detention population was 33,330 (see Figure 1 ). Of all detainees, 67.0% were from Mexico, and they tended to have shorter stays in detention than other nationality groups. The other leading countries for the percentage of total detainees were Guatemala (9.0%), Honduras (6.2%), and El Salvador (5.5%). Some maintain that DHS detains too many people who are not a threat to public safety and that the money spent to detain such people could be better spent on other enforcement priorities. They argue that the increase in the number of classes of aliens subject to mandatory detention has impacted the availability of detention space for lower priority detainees and has also affected ICE's ability to exercise discretion in determining who to detain or release. Others contend that DHS should be detaining more noncitizens to help effectuate removal but does not have enough detention space to house all those who should be detained. They also argue that detention is necessary to protect public safety, and to deter illegal border crossers and false asylum claims. In FY2011, there were approximately 480,000 noncitizens in the United States who had been ordered deported and could not be confirmed to have left the country. A study done by DOJ's Inspector General in 2003, found that almost 94% of those detained with final orders of removal were deported while only 11% of those not detained who were issued final orders of removal left the country. In addition, in 2007, then ICE director John Torres testified that 90% of aliens released from detention did not appear for their immigration hearings. Furthermore, concerns have been raised that decisions on which aliens to release and when to release the aliens may be based on the amount of detention space, not on the merits of individual cases. The amount of space varies by area of the country, and may lead to inequities and disparate policies in different geographic areas. In addition, moving detainees between detention facilities, often relocating them to an area away from where they were arrested, has been shown to delay hearings and increase the time a person is in detention, which increases detention costs. The overall increase in the number of noncitizens in DHS detention has also focused attention on the cost of detaining noncitizens, especially as Congress tries to balance immigration enforcement priorities and a tight fiscal budget. For FY2012, it cost DHS an average of $118 a day for each detainee held in detention. This cost does not include transportation or the cost of deporting the alien, and differs by type of detention facility. In comparison, for FY2004, DHS budgeted $97 (in 2012 dollars) a day for each detainee held in detention. As Table 1 shows, funding for ICE's detention operations increased between FY2008 and FY2012, even as the fiscal climate has become more constrained. In FY2010 and FY2011, Congress appropriated similar amounts for custody operations, funding 33,400 beds in both years. (See Figure 1 .) In FY2012, Congress increased the number of beds by 600, and increased funding for custody operations by $257 million. Due to the cost of detaining aliens, and the fact that many non-detained aliens with final orders of removal do not leave the country, there has been interest in developing alternatives to detention for certain types of aliens who do not require a secure detention setting. On June 21, 2004, ICE began a pilot program for low-risk, non-violent offenders in eight locations. The program, the Intensive Supervision Appearance Program (ISAP), provides less restrictive alternatives to detention, using such tools as electronic monitoring devices (e.g., ankle bracelets), home visits, work visits, and reporting by telephone, to monitor aliens who are out on bond while awaiting hearings during removal proceedings or the appeals process. The Department of Homeland Security Appropriations Act for FY2012 appropriated $72.4 million for alternatives to detention, including the ISAP. In the 112 th Congress, bills were introduced that covered a range of provisions and perspectives concerning the detention of noncitizens. Several bills--including H.R. 100 and H.R. 1274 --would have mandated that DHS increase the amount of detention space. In addition, other bills (e.g., H.R. 933 , S. 1258 ) would have required the propagation of regulations concerning detainee care, and expanded the alternatives to detention program. Other proposed legislation, such as H.R. 713 , would have made changes to the mandatory detention provisions, providing the administration with more discretion on who should be detained. Only one bill, H.R. 1932 , received any Congressional action. On October 18, 2011, the House Judiciary Committee reported the Keep Our Communities Safe Act of 2011 ( H.R. 1932 ). Among other things, H.R. 1932 would have codified and modified the conditions for post-removal order detention. The bill would have allowed DHS to detain indefinitely, subject to six-month reviews, an alien under orders of removal who could not be removed if (1) there was a significant likelihood that the alien would be removed in the reasonably foreseeable future; (2) the alien would have been removed but for the alien's refusal to cooperate with the DHS Secretary's identification and removal efforts; (3) the alien had a highly contagious disease that posed a public safety threat; (4) release would have had serious adverse foreign policy consequences; (5) release would have threatened national security; (6) release would have threatened the safety of the community, and the alien had either been convicted of one or more aggravated felonies or other designated crimes or been convicted of one or more crimes of violence and due to a mental condition or personality disorder was likely to engage in future acts of violence; or (7) release would have threatened the safety of the community, and the alien has been convicted of at least one aggravated felony. The bill would have limited habeas corpus reviews of such detention and related actions or decisions to the U.S. District Court for the District of Columbia. Also, the bill would have permitted unlimited detention of certain aliens during pending removal proceedings. Proponents of H.R. 1932 contended that legislation is needed to prevent criminal aliens who cannot be removed to their home countries from being released and committing additional crimes. They argued that the Supreme Court in Zadvydas v. Davis (2001), did not deny Congress the authority to provide for extended periods of detention. Indeed, they contended that the Court "invited" Congress to amend existing law to clarify circumstances and procedures under which extended detention would be permissible. Nonetheless, others argued that the criminal justice and civil commitment systems already exist to keep dangerous individuals away from the public. They also contended that H.R. 1932 would allow for the prolonged, unnecessary, and expensive detention of asylum seekers and other immigrants by preventing bond determination hearings and limiting habeas corpus review to the U.S. District Court for the District of Columbia. The number of noncitizens in immigration detention and the funding for immigration detention has increased fairly steadily over the past decade. Under law, there is broad authority to detain noncitizens in the United States while awaiting a determination of whether the alien should be removed from the country. In addition, the law specifies certain categories of aliens that must be detained while the Secretaries of DHS and the Attorney General, operating through their delegates, can parole or release on bond aliens who are not mandatory detainees. Aliens in immigration detention have certain rights, but the courts have afforded the Administration much discretion in decisions related to where aliens are detained, the management of detention facilities, and the treatment of aliens. Congressional interest in detention policy has included hearings and legislation dealing with concerns about the number of aliens subject to mandatory detention; the justness of mandatory detention; detention conditions; and the proper limits on the length of time in detention for aliens who have been ordered removed but cannot be returned to their home country.

Summary:
The 113th Congress may consider a comprehensive reform of the nation's immigration system (CIR), and during such discussions, the detention of noncitizens in the United States might be an issue. Congress may choose to reevaluate detention priorities (i.e., who should be detained, when they should be detained) and detention resources. Under the law, there is broad authority to detain foreign nationals (aliens/noncitizens) while awaiting a determination of whether the noncitizen should be removed from the United States. The law also mandates that certain categories of aliens are subject to mandatory detention (i.e., the aliens must be detained). Aliens subject to mandatory detention include those arriving without documentation or with fraudulent documentation, those who are inadmissible or deportable on criminal grounds, those who are inadmissible or deportable on national security grounds, those certified as terrorist suspects, and those who have final orders of deportation. Aliens not subject to mandatory detention may be detained, paroled, or released on bond. The priorities for detention of these aliens are specified in statute and regulations. For example, the Illegal Immigrant Reform and Immigrant Responsibility Act of 1996 (IIRIRA) increased the categories of aliens subject to mandatory detention. This increase has raised concerns about the justness of mandatory detention, especially as it is applied to asylum seekers arriving without proper documentation. As of December 22, 2012, on an average day in FY2013, there were 34,696 noncitizens in Department of Homeland Security (DHS) custody. The amount of detention space is almost exclusively controlled by Congress through appropriations, and Congress has been active in providing oversight of detention space allocations and detention conditions. Since FY2002, Congress has increased the number of funded detention beds from 21,109 beds to 34,000 beds. As DHS increases its ability to identify aliens who are subject to removal from local jails in more remote locations, the nationwide allocation of detention space may become an issue. Furthermore, the detention policy for aliens who have received a final order of removal may also be a congressional concern. After a final removal order has been issued against an alien, the law provides that the alien be removed within 90 days, except as otherwise provided in the statute. Certain aliens subject to a removal order "may be detained beyond the removal period and, if released, shall be subject to [certain] terms of supervision." This provision had been interpreted as permitting indefinite detention where removal was not reasonably foreseeable, but in 2001, the U.S. Supreme Court in Zadvydas v. Davis, interpreted it as only permitting detention for up to six months where removal was not reasonably foreseeable. Nonetheless, the U.S. Supreme Court stated that its ruling was made "absent clear guidance from Congress" (i.e., that it was not clear what congressional intent was related to detaining aliens who could not be removed within 90 days). Comprehensive immigration reform (CIR) bills in the 109th and 110th Congress would have modified and codified the regulations regarding the detention of those with final orders of removal. In the 112th Congress, H.R. 1932, as reported by the House Judiciary Committee would have amended the Immigration and Nationality Act to allow DHS to indefinitely detain, subject to six-month reviews, aliens under orders of removal who could not be removed if certain conditions were met.