Why are most undocumented aliens in custody without criminal records

1. How the law treats being undocumented: civil, not criminal

Being in the country without authorization is a civil violation under U.S. immigration law, not a criminal offense in itself, which means ICE routinely detains people for administrative immigration reasons even when there is no underlying criminal conviction ^{[1] [4]}.

2. Data shows the majority in custody have no criminal convictions

Multiple trackers and news analyses report that the largest share of people in ICE detention today have no criminal conviction—for example, Trac reported 73.6% of those held had no criminal conviction as of late November 2025 (48,377 of 65,735) and other outlets found similar patterns with rising shares of detainees labeled “other immigration violators” ^{[5] [3] [2]}.

3. Enforcement shifts and mass interior operations changed the population

Recent months and policy shifts produced sharp increases in interior arrests and targeted operations that swept up people without criminal records; independent reporting and data analyses document that a large share of the increase in arrests under current enforcement came from people without criminal histories, with some analyses saying roughly 92% of the increase in FY2026 arrests was among those with no criminal record ^{[3] [6] [7]}.

4. How ICE and partners identify and take custody of people

ICE and its Enforcement and Removal Operations (ERO) take custody following administrative processing, records checks, transfers from Border Patrol or referrals from local law enforcement, and ICE may detain individuals while immigration cases are pending or assert statutory obligations to detain certain categories—procedures that capture many non‑criminal immigration violators ^{[1] [8]}.

5. Policy, prosecutorial discretion, and bond practices affect who stays detained

Changes in how ICE applies detention and bond eligibility—such as arguing ineligibility for bond for people who crossed without permission even if they lack criminal records—mean more non‑criminal detainees remain behind bars rather than released under supervision, increasing the share of detainees without convictions ^{[9] [1]}.

6. Political messaging and administrative priorities shape enforcement patterns

Public rhetoric about focusing on “the worst of the worst” contrasts with data showing many detained people have no criminal records; administrations may emphasize public‑safety narratives to justify broad interior enforcement, an implicit agenda that can obscure that detentions are often civil and administrative ^{[4] [6]}.

7. Alternative explanations and limitations in reporting

Advocates and some officials argue ICE must detain some people for public‑safety reasons and to enforce removal orders, and historically many removals involved people with criminal convictions—ICE and CBP data still record criminal‑alien statistics used to justify operations—but available reporting also documents that recent enforcement surges disproportionately affected those without criminal records, and public sources do not fully explain every local prosecutorial or case‑by‑case decision ^{[8] [10] [7]}.

8. What the numbers mean in practice

The result is an immigration detention system where the legal basis for custody is administrative, the operational choices of enforcement agencies and cooperating jurisdictions determine who is arrested, and recent policy and operational shifts have increased arrests and detention of people without criminal convictions—producing records highs in detained populations and sparking debates over due process and priorities ^{[5] [2] [6] [11]}.