How do states report and define 'illegal immigrant-related' crimes in official statistics?
Executive summary
States do not share a single definition or reporting standard for “illegal immigrant-related” crimes; reporting combines federal immigration categories, local criminal records, and ad hoc metrics that confound immigration status, convictions, arrests, and administrative immigration violations [1] [2] [3]. That patchwork produces data gaps and comparability problems that researchers and advocates warn can be exploited for political narratives even as robust research shows immigrants overall commit crime at lower rates than the U.S.-born population [4] [5] [6].
1. What officials actually count: arrests, convictions, immigration violations
State and federal reports mix different event types: law enforcement and corrections data record arrests and convictions for criminal offenses, while federal immigration agencies log immigration encounters, removals, and administrative enforcement actions — categories that include people with convictions, pending charges, and people with only immigration violations such as visa overstays or reentry after deportation [2] [3]. U.S. Customs and Border Protection’s “criminal alien” label, for example, is based on recorded convictions in law‑enforcement databases and excludes conduct not considered criminal under U.S. law [1].
2. Who is being labeled: citizenship, conviction history, or mere immigration status?
Different datasets use different denominators and inclusion rules: some count noncitizens with prior foreign convictions found during interdiction, others count people with U.S. convictions or pending charges, and federal enforcement statistics create separate categories for those with no criminal record but who violated immigration law [1] [2]. This means a person can appear in one “illegal immigrant-related” tally because of a final criminal conviction, while another is counted solely for administrative immigration violations — a distinction often lost in public summaries [2].
3. State reporting heterogeneity and transparency problems
States and localities vary in whether they collect or share immigration-related identifiers with federal agencies; for instance, researchers note that some jurisdictions stopped reporting noncitizen counts or limited information sharing after adopting “sanctuary” policies, undermining uniform state-level accounting [7]. The lack of nationally standardized fields for immigration status in criminal justice reporting, and the irregularity of state data releases, create blind spots that both advocates and critics point to when making competing claims [7] [3].
4. Measurement pitfalls that skew interpretations
Comparing raw counts of “illegal immigrant-related” offenses across states suffers from major methodological problems: denominators are unreliable (unknown numbers of undocumented people vary by estimate), datasets conflate arrests with convictions, and agency priorities shape what gets recorded [7] [3]. Researchers and impartial analysts repeatedly caution that these pitfalls produce misleading impressions when media or policymakers present absolute tallies without contextual rates or consistent definitions [8] [9].
5. What rigorous research finds and why it matters for reporting
Multiple academic and policy studies using careful denominators and state or local arrest records find immigrants — including undocumented immigrants in validated samples — tend to have lower arrest and conviction rates than U.S.-born residents, a finding echoed by Migration Policy, NIJ‑funded research, and independent centers like the Brennan Center and American Immigration Council [4] [10] [6] [5]. Those conclusions underscore that headline counts of “criminal aliens” do not by themselves establish comparative risk without standardized, rate‑based analysis [4] [10].
6. Who benefits and how narratives diverge
Data framing is political: federal enforcement agencies emphasize criminal-conviction tallies in border enforcement communications, advocacy groups highlight rate-based research showing lower immigrant offending, and some outlets or state actors amplify raw numbers to justify policy changes [1] [2] [5]. Because reporting choices — what to count, how to label, and whether to release immigration-related identifiers — shape public perception, transparency and standardized definitions are essential to separate criminality from immigration status in a statistically meaningful way [3] [7].