What are the primary reasons ICE cited for detaining U.S. citizens in recent years (e.g., mistaken identity, data errors, warrant issues)?

1. What ICE and DHS say: targeted enforcement, not citizen detentions

The Department of Homeland Security and ICE publicly insist that enforcement operations are highly targeted and that agents verify status before detaining people, repeatedly denying that the agencies are systematically arresting U.S. citizens ^{[3] [4]}. DHS spokespeople and press releases frame most disputed incidents as lawful arrests for assault or obstruction or as quickly corrected mistakes; the department says procedures exist to determine removability and that detainees receive treatment under detention standards ^{[5] [3] [6]}.

2. What watchdogs and journalists found: mistaken identity, bad data, and weak tracking

Investigations by ProPublica, The Guardian, PBS, Politifact and others documented scores of U.S. citizens detained during 2025 enforcement operations and found systemic problems: ICE’s data systems do not consistently require updating the citizenship field after investigations, and GAO concluded ICE does not systematically track citizenship investigations — conditions that produce wrongful detentions tied to outdated records and identification errors ^{[1] [2] [7]}. Congressional inquiries and NGO reports emphasize poor record‑keeping as a key driver of these errors ^{[8] [2]}.

3. Primary reasons cited in reporting for citizen detentions

Reporting and oversight point to several recurring causes: (a) misidentification and visual profiling during raids and street stops, where people “who looked Latino” were swept up; (b) database errors and outdated citizenship fields that fail to reflect later-corroborated U.S. status; (c) biometric or facial‑recognition mismatches that produced false positive matches; and (d) the creation or use of warrants and detainers without adequate verification — all leading to short- and longer-term detention of citizens ^{[9] [2] [10] [11]}.

• Misidentification and racial profiling are described as drivers in multiple accounts, with advocates and Human Rights Watch saying perceived race or national origin influenced who agents targeted ^{[9] [12]}.
• Data and record errors — including an ICE requirement that officers document but not always update citizenship fields — underlie many wrongful detentions, per the GAO review ^[2].
• Biometric and face‑scan errors are specifically documented as triggering at least some wrongful detentions; senators and reporting cite at least one 30‑hour wrongful detention tied to an “incorrect biometric confirmation” ^[10].
• Warrant and arrest-practice issues appear in lawsuits and local reporting: local warrants, detainers, and warrantless interior arrests have led to legal challenges and claims that agents failed to have probable cause before detaining people later shown to be citizens ^{[13] [14]}.

4. How many citizens were affected — the numbers dispute

There is no single official tally. ProPublica reported more than 170 U.S. citizens held by immigration agents in 2025; congressional letters and local reporting cite dozens of cases; GAO and other data projects say ICE does not have reliable counts because of inconsistent practices ^{[1] [8] [2]}. ICE and DHS deny there is credible evidence of systemic detentions and argue isolated errors are corrected; journalistic tallies and advocacy groups say that undercounting and missing transparency hide the true scope ^{[4] [15]}.

5. Where accounts diverge and why that matters

Government denials focus on policy and intent; watchdogs and victims focus on outcomes. DHS emphasizes training, procedures and that mistakes are rare and corrected ^{[5] [3]}. Reporters, GAO and civil‑rights groups point to empirical patterns (biometric false positives, database mistakes, use of visual markers) and to the practical harm of even intermittent wrongful detention — including time in custody, missed legal access and family separation ^{[2] [16] [9]}.

6. Limits of the available reporting and next steps to clarify the record

Sources show consistent problems with tracking and transparency but disagree on scale. ICE’s public datasets have gaps, and the government shutdown in late 2025 temporarily halted published detention data, making independent verification harder ^{[17] [15]}. Congress and civil‑rights groups have demanded investigations and better recordkeeping; GAO recommended stronger tracking of citizenship investigations — reforms that would produce clearer numbers if implemented ^{[8] [2]}.

Conclusion: available sources document multiple, recurring mechanisms — misidentification, database and biometric errors, and problematic warrant/booking practices — that have led ICE or related agents to detain people later shown to be U.S. citizens, even as DHS disputes the prevalence and emphasizes corrective procedures ^{[2] [12] [3]}.