A detention center, in the way the term is most commonly used, is a federal facility that holds noncitizens while the government decides whether to remove them from the country. A jail is a locally run facility that holds people charged with or convicted of crimes. Both lock people behind the same kinds of doors, but they run on entirely separate legal tracks, and that split shapes almost everything else: who gets a free lawyer, how long a stay lasts, how someone gets out, and what a family can do about it.
Who Runs Each Facility and Under What Law
Immigration detention is federal and civil. U.S. Immigration and Customs Enforcement describes its detention system as “non-punitive,” designed to secure a person’s presence for immigration proceedings or removal rather than to punish them for a crime.1U.S. Immigration and Customs Enforcement. Detention Management ICE’s authority to arrest and hold people comes from the Immigration and Nationality Act, which lets the agency detain anyone it has reason to believe is removable from the United States.2Office of the Law Revision Counsel. 8 USC 1226 – Apprehension and Detention of Aliens
Jails are the opposite: local, criminal, and run by county or municipal governments. Their authority comes from state and local criminal law. The point of a jail is accountability for criminal conduct, not administrative processing of someone’s immigration status.
One thing that surprises many families: a large share of immigration detainees are actually held in local jails or privately operated facilities under contract with ICE, not in purpose-built federal buildings. ICE requires every facility housing its detainees to follow federal detention standards regardless of who owns the building.1U.S. Immigration and Customs Enforcement. Detention Management So the legal framework governing a person’s confinement depends on why they are being held, not necessarily on the sign over the door.
Who Ends Up in Each
Immigration detention centers hold noncitizens caught up in the removal process. That includes asylum seekers waiting for a hearing, long-term residents who lost their status after a criminal conviction, and people picked up during workplace enforcement. The common thread is that the detention relates to immigration status. Unaccompanied children are handled separately by the Office of Refugee Resettlement within the Department of Health and Human Services, not by ICE.1U.S. Immigration and Customs Enforcement. Detention Management
Jails hold a much broader mix. On any given day, most people inside are pretrial detainees who have been charged but not yet convicted—they could not post bail, a judge denied bail, or they are waiting for a first appearance. The rest are serving sentences for misdemeanors or low-level felonies, usually under one year. Populations turn over quickly with local arrest patterns and court schedules.
The Right to a Lawyer
This is the difference that catches the most families off guard. If you are charged with a crime and held in jail, the Sixth Amendment guarantees you a lawyer. If you cannot afford one, the court must appoint one for you.3Legal Information Institute. Sixth Amendment That right kicks in as soon as formal criminal proceedings begin and covers every critical stage.
In immigration detention, no equivalent right exists. Federal law says a person in removal proceedings has “the privilege of being represented” by counsel, but adds four words that carry all the weight: “at no expense to the Government.”4Office of the Law Revision Counsel. 8 USC 1362 – Right to Counsel The government will not appoint a free attorney. Detainees have to find and pay for their own, which is extremely hard to do from inside a locked facility with limited phone access and no internet. Pro bono referrals happen when possible, but demand far exceeds the supply.
How Long People Stay
Jail stays tend to be short. Pretrial detainees are either released on bail, resolve their case, or get transferred to state prison after sentencing. Misdemeanor sentences are under a year by definition. The rhythm is high turnover.
Immigration detention is far less predictable. Some people are released on bond within days. Others spend months or years waiting for their case to work through the immigration court backlog. Average stays in ICE custody have hovered around 40 to 50 days in recent years, but that average hides enormous variation. A straightforward deportation case may resolve quickly; a contested asylum claim can drag on much longer.
Mandatory Detention
Some noncitizens cannot be released on bond at all. Federal law requires the government to take into custody anyone deportable for an aggravated felony, a controlled substance offense, certain firearms offenses, or specific national security-related grounds. The only narrow exception is release for a person cooperating as a witness in a major criminal investigation who satisfies the government that they pose no danger and will show up.2Office of the Law Revision Counsel. 8 USC 1226 – Apprehension and Detention of Aliens
The Limit on Indefinite Detention
For people with a final removal order who cannot actually be deported because no country will take them, the Supreme Court set a constitutional limit. In Zadvydas v. Davis (2001), the Court held that the government cannot detain someone indefinitely after a removal order, and it established a presumptive six-month period as reasonable.5Legal Information Institute. Zadvydas v. Davis After six months, if there is no significant likelihood of removal in the reasonably foreseeable future, the detainee can seek release. No comparable constitutional cap governs pretrial jail detention, where the timeline runs on speedy trial rules and the court’s calendar.
Conditions and Standards Inside
Because immigration detention is classified as civil rather than criminal, the facilities are supposed to feel different from jails. In practice, many immigration detainees are held in buildings that look and feel exactly like jails, with cells, uniforms, and controlled movement. The written standards, though, are different.
ICE facilities must comply with the National Detention Standards, which cover recreation, grievances, religious accommodations, and more.1U.S. Immigration and Customs Enforcement. Detention Management Under those standards, every new arrival must receive an initial medical, dental, and mental health screening within 12 hours, and anyone reporting a serious or chronic condition must be seen by a licensed healthcare practitioner within two working days.6U.S. Immigration and Customs Enforcement. 4.3 Medical Care – National Detention Standards Revised 2019
Jails answer to a constitutional floor rather than detailed federal rules. The Eighth Amendment prohibits cruel and unusual punishment, and courts have read that to require adequate medical care. But the operative legal standard is “deliberate indifference to serious medical needs,” a high bar: a jail violates the Constitution only when officials know of a substantial risk of harm and fail to act, not when care is merely slow or thin by outside standards.7Legal Information Institute. Prisoners’ Rights State jail standards commissions add their own rules, and conditions vary considerably across the country.
Getting Out
The two systems use entirely different release processes, with different decision-makers and different rights attached.
Release From Jail
Release from a jail usually happens through bail or personal recognizance. A judge sets bail at arraignment based on the severity of the charge, criminal history, and flight risk. Post the bail, and the defendant goes home and returns for court dates. Many jurisdictions also use pretrial services programs that supervise defendants through check-ins or electronic monitoring. After a conviction, parole boards or good-time credits can shorten a sentence.
Release From Immigration Detention
For noncitizens not subject to mandatory detention, ICE first makes its own custody determination, which may include release on bond. The statutory minimum bond is $1,500, though actual bonds set by ICE are often much higher.2Office of the Law Revision Counsel. 8 USC 1226 – Apprehension and Detention of Aliens If the bond seems too high, the detainee can request a bond hearing before an immigration judge, who has authority to lower the amount.8Executive Office for Immigration Review. 8.3 – Bond Proceedings The judge decides whether the person is a flight risk or a danger to the community.
ICE also runs an Alternatives to Detention program for people released from custody, using three tiers of supervision: telephonic check-ins that verify identity through voiceprint matching, GPS ankle monitors, and a smartphone app called SmartLINK that uses facial recognition and periodic location check-ins.9U.S. Immigration and Customs Enforcement. Alternatives to Detention
The endings are different too. A jail stay ends in acquittal, dismissal, a plea, a sentence served, or transfer to prison. An immigration detention stay ends in deportation, a grant of relief such as asylum, or release into the community pending further proceedings. There is no “serving a sentence” in immigration detention, because the detention itself is not a sentence.
When the Two Systems Collide
The two tracks intersect more often than people realize. When a noncitizen is arrested on criminal charges and held in a local jail, ICE may lodge an immigration detainer, formally called Form I-247A. The detainer asks the jail to hold the person for up to 48 hours beyond the time they would otherwise be released on the criminal matter so ICE can take custody.10Department of Homeland Security (ICE). Immigration Detainer – Notice of Action (DHS Form I-247A)
ICE’s authority to issue these detainers comes from federal regulations at 8 C.F.R. § 287.7, which derives from the Secretary’s power under the Immigration and Nationality Act.11U.S. Immigration and Customs Enforcement. Immigration Detainers Whether a local jail honors a detainer varies. Some jurisdictions comply as a matter of policy; others limit or refuse cooperation. For the person inside, the practical effect is that resolving a criminal case does not necessarily mean going home. A detainer can turn the last day of a jail stay into the first day of a deportation process.
Suing Over Conditions
The remedies available when things go wrong inside also split along federal-versus-local lines. If you are in a local jail and a state or county official violates your constitutional rights, you can sue under 42 U.S.C. § 1983, which imposes civil liability on anyone acting under color of state law who deprives another person of federally protected rights.12Office of the Law Revision Counsel. 42 US Code 1983 – Civil Action for Deprivation of Rights
No equivalent statute covers federal officials. A person in federal custody alleging a constitutional violation has to rely on the Bivens doctrine, named after a 1971 Supreme Court case that recognized an implied right to sue federal agents for Fourth Amendment violations.13Legal Information Institute. Bivens v. Six Unknown Named Agents of Federal Bureau of Narcotics The Supreme Court has narrowed Bivens substantially over the years, making it extremely difficult to bring new types of claims against federal officials. For an immigration detainee alleging mistreatment by federal staff, the legal terrain is far less favorable than what a jail inmate could pursue under Section 1983.
Which Court Decides the Case
Immigration cases are heard by immigration judges within the Executive Office for Immigration Review, a division of the Department of Justice.14U.S. Department of Justice. Executive Office for Immigration Review These judges handle bond hearings, asylum claims, and removal cases. Immigration court is not part of the independent federal judiciary; immigration judges are Justice Department employees, meaning the same executive branch trying to deport someone also controls the court deciding the case. That structural feature has drawn criticism for decades.
Criminal cases run through state courts, where judges handle arraignments, trials, and sentencing under the full protections of the Constitution, including the Eighth Amendment ban on cruel and unusual punishment and the Fourteenth Amendment’s due process and equal protection guarantees.7Legal Information Institute. Prisoners’ Rights
Finding Someone in Custody
Locating a person requires different tools depending on which system is holding them. For immigration detainees, ICE runs the Online Detainee Locator System. To search, you need the person’s full legal name along with either their alien registration number (A-number) or their date of birth and country of birth.15U.S. Immigration and Customs Enforcement. Locating Individuals in Detention Without those details, the system will not return results, which can be a real obstacle for families who do not have immigration paperwork on hand.
For local jails there is no single national database. Most county jails maintain their own online inmate rosters searchable by name. A broader option is the VINE (Victim Information and Notification Everyday) network, which aggregates custody status from thousands of law enforcement agencies across most states and can send automatic notifications when a person’s status changes. The simplest step is often calling the jail directly and asking about a specific person by name and date of birth.