The Enforcers: Inside U.S. Immigration and Customs Enforcement (ICE)

Marcelo Serafim
6 days ago
5 min read

U.S. Immigration and Customs Enforcement, commonly known as ICE, is a federal law enforcement agency under the Department of Homeland Security (DHS). Established in 2003, ICE was born out of the massive government reorganization that followed the September 11, 2001, terrorist attacks. The Homeland Security Act merged the investigative and enforcement arms of the former U.S. Customs Service and the Immigration and Naturalization Service (INS) into a single agency. Its creation was driven by a post-9/11 desire to better connect national security with border control and immigration enforcement.

The agency’s mission is vast and dual-pronged, often leading to public confusion. While the U.S. Border Patrol (CBP) operates directly at the borders, ICE is responsible for interior enforcement—operating inside the United States. Its mandate is to protect the country from cross-border crime and illegal immigration that threatens national security and public safety. To achieve this, ICE is divided into two primary directorates: Enforcement and Removal Operations (ERO) and Homeland Security Investigations (HSI).

Enforcement and Removal Operations (ERO) is the branch most visible to the public and the subject of the most intense controversy. ERO officers are responsible for identifying, arresting, detaining, and deporting non-citizens who have violated U.S. immigration laws. This includes individuals who entered the country illegally, those who overstayed their visas, and legal residents who have committed crimes that make them deportable. ERO manages a massive logistical network involving transportation and detention facilities across the country to process these removals.

In contrast, Homeland Security Investigations (HSI) operates more like a traditional federal police force, similar to the FBI. HSI agents investigate transnational crimes that span global borders. Their focus is not just on undocumented immigrants, but on criminal organizations involved in human trafficking, drug smuggling, weapons proliferation, cybercrime, and art theft. Because their work focuses on serious criminal threats rather than civil immigration violations, HSI often operates with less public scrutiny than their ERO counterparts.

ICE possesses broad and unique legal powers. Unlike local police, ICE officers can arrest individuals for civil violations of immigration law, often without a warrant signed by a judge. They frequently use "administrative warrants," which are issued by the agency itself. This authority allows them to detain individuals pending a court hearing. Additionally, ICE issues "detainers"—requests to local jails to hold individuals for up to 48 hours beyond their scheduled release so ICE can take them into custody, a practice that has sparked significant legal battles with "sanctuary cities."

The agency manages one of the largest civil detention systems in the world. On any given day, tens of thousands of individuals are held in a network of county jails and privately owned prisons contracted by the federal government. These facilities are designed to hold people while their immigration cases are processed or while they await deportation. However, because immigration violations are often civil, not criminal, detainees are not guaranteed a court-appointed lawyer, leading to complex legal struggles for those inside.

Oversight of ICE is theoretically handled by several bodies, including the DHS Office of Inspector General (OIG) and the recently created Office of the Immigration Detention Ombudsman (OIDO). These independent bodies are tasked with auditing ICE’s finances and investigating allegations of misconduct or abuse within detention centers. Congress also holds the power of the purse, funding the agency and holding hearings to question its leadership. However, critics often argue that these oversight mechanisms lack the "teeth" to enforce real changes or penalties for misconduct.

Recent years have seen ICE become a lightning rod for political controversy, particularly regarding humanitarian concerns. Reports from 2024 and 2025 highlighted a sharp rise in deaths within ICE custody and widely criticized medical neglect in detention centers. Human rights groups have documented severe overcrowding and the use of solitary confinement, sparking lawsuits and international condemnation. The legacy of family separation policies at the border continues to haunt the agency's reputation, fueling demands for reform.

Another major controversy revolves around the expansion of "mandatory detention." Recent policy shifts have barred immigration judges from releasing many detainees on bond, meaning individuals—including asylum seekers with no criminal record—must remain locked up for months or years while their cases drag through clogged courts. This has led to a ballooning detention population and accusations that the agency is prioritizing "mass incarceration" over fair legal processes.

Today, ICE stands at the center of a polarized American debate. Supporters view the agency as essential for maintaining rule of law and national sovereignty, arguing that strict enforcement is the only way to deter illegal migration. Opponents, including the "Abolish ICE" movement, argue the agency has become a rogue force that terrorizes communities and violates human rights. As immigration remains a top political issue, ICE’s role, funding, and tactics continue to evolve with every change in presidential administration.

Comprehension Questions

What two former government agencies were merged to create ICE?
What is the primary difference between ERO and HSI?
How does an "administrative warrant" differ from a standard judicial warrant?
Why has the practice of issuing "detainers" caused conflict with some local cities?
What recent policy change regarding "mandatory detention" is mentioned in the text?

Vocabulary List

Here are 10 challenging words from the text with their definitions:

Mandate (n.): An official order or commission to do something; the authority to carry out a policy.
Transnational (adj.): Extending or operating across national boundaries.
Logistical (adj.): Relating to the detailed organization and implementation of a complex operation.
Proliferation (n.): Rapid increase in numbers; often used regarding the spread of weapons.
Scrutiny (n.): Critical observation or examination.
Detainer (n.): A legal order to hold a person in custody, specifically an ICE request to a local jail.
Ombudsman (n.): An official appointed to investigate individuals' complaints against maladministration, especially that of public authorities.
Asylum (n.): The protection granted by a nation to someone who has left their native country as a political refugee.
Sovereignty (n.): The authority of a state to govern itself or another state.
Polarized (adj.): Divided into two sharply contrasting groups or sets of opinions.

Phrasal Verb Focus

Phrasal Verb: Crack down on

Meaning: To start dealing with bad or illegal behavior in a more severe way; to enforce laws or rules more strictly.
Context: ICE was created to crack down on security threats after 9/11.

Examples:

"The school principal promised to crack down on bullying."
"The government is cracking down on tax evasion this year."
"Police are cracking down on speeding in the school zone."

American Idiom Focus

Idiom: Under the radar

Meaning: To do something without being noticed or detected; to keep a low profile.
Context: Many undocumented immigrants try to live under the radar to avoid detection by ICE ERO agents.

Examples:

"He tried to keep his mistake under the radar so his boss wouldn't find out."
"The small indie movie flew under the radar but ended up winning an award."

Grammar Tip: Relative Clauses

Relative clauses add information about a noun. They usually start with who (for people), which/that (for things), or where (for places).

1. Defining Relative Clauses (Essential info): These tell us which person or thing we are talking about. No commas are used.

Text: "Individuals who entered the country illegally are subject to deportation."
- (If we remove the bold part, we don't know which individuals we are talking about.)

2. Non-Defining Relative Clauses (Extra info): These give extra, nice-to-know information. We use commas.

Text: "HSI, which operates like a traditional police force, investigates transnational crime."
- (We know what HSI is; the clause just gives extra detail. If we remove it, the sentence still makes sense.)

Listening

Homework Proposal

Task: "The Town Hall Meeting"

Imagine you are a mayor of a fictional U.S. city. You must decide whether your city will cooperate fully with ICE or become a "Sanctuary City" (limiting cooperation).

Write a speech (1 paragraph) announcing your decision to the town.
Use specific vocabulary: Use at least three words from the Vocabulary List (e.g., Mandate, Jurisdiction, Detainer).
Grammar Requirement: Include one Non-Defining Relative Clause (e.g., "Our city, which values safety, will...")