Illegal Aliens & Crime

Illegal Aliens & Crime


This compilation and analysis of the facts about illegal aliens and crime was authored by John Perazzo in February 2023.


For decades, the defenders of open-borders immigration policies have consistently claimed that illegal aliens commit less crime than native-born American citizens. But that claim is typically based on studies that deceptively manipulate data in a manner designed to support that particular narrative. For example, many studies fail to distinguish between illegal aliens and their legal immigrant counterparts, instead conflating the two groups and citing them all generically as “immigrants.” And as Peter Kirsanow of National Review points out: “Illegal-immigrant crime calculations conveniently and invariably steal a base by leaving out the millions of crimes committed by illegal immigrants related to procuring fraudulent social security numbers, obtaining false drivers’ licenses, using fraudulent green cards, and improperly accessing public benefits.”

“That error is then compounded,” notes the Federation for American Immigration Reform (FAIR), “when researchers intentionally elect to leave out broad classes of crimes, for example, drug offenses — as the Cato Institute frequently does.” Moreover, FAIR explains: “[M]ost federal, state and local government agencies do not collect data on the rates at which illegal aliens are convicted of crimes. Most likely, this is due to political correctness, and a desire to keep the truth about the number of crimes committed by illegal aliens from coming to light.” But “examinations of data on criminal activity by known illegal aliens tend to establish that those who enter the U.S. in violation of our immigration laws also commit other crimes at a higher rate,” reports FAIR, adding: “This should not be surprising to anyone. The simple fact that illegal aliens violated American immigration laws – and must continuously violate other federal, state and local laws in order to mask their ongoing illegal presence in this country – demonstrates a blatant lack of respect for the rule of law.”

The Evidence

Let us examine, more or less chronologically, some of the more noteworthy research that has focused on the criminality of illegal aliens in the United States.

In 2005, the Government Accountability Office (GAO) released a report that looked at the criminal histories of 55,322 aliens who had “entered the country illegally and were still illegally in the country at the time of their incarceration in federal or state prison or local jail during fiscal year 2003.” Over the course of their criminal careers, those 55,322 illegals had been arrested a combined 459,614 times — an average of 8.3 arrests apiece — and had committed almost 700,000 separate criminal offenses, or roughly 12.7 offenses each. Approximately 12 percent of their arrests were for violent crimes such as homicide, robbery, assault, and sex-related offenses; 15 percent were for property offenses like burglary, larceny, theft, and vandalism; 24 percent were for drug crimes; and the rest were for a wide array of transgressions like DUI, fraud, forgery, counterfeiting, weapons violations, immigration crimes, and obstruction of justice.

A 2011 study by the GAO found that according to data provided by the State Criminal Alien Assistance Program (SCAAP) — a federal government initiative through which states apply to have the U.S. Immigration & Customs Enforcement (ICE) agency partially reimburse them for the costs associated with keeping both known and suspected illegal aliens behind bars — a total of 295,959 criminal aliens were incarcerated in state jails and prisons across the United States during Fiscal Year 2009. Approximately 227,600 of them – or 77 percent — were in the U.S. illegally at the time. And the crimes they committed were very often of a serious or grave nature. Indeed, the GAO study examined in particular five states with large illegal alien populations – Arizona, California, Florida, New York, and Texas. Setting aside traffic offenses, 41 percent of all illegal-alien convictions in Arizona were for drug crimes and assault. In California and Texas, about half of all illegal-alien convictions were for drugs, assault, and sex offenses. In Florida, roughly 50 percent were for drug offenses, sex crimes, burglary, and robbery. And in New York, 23 percent were for drug-related offenses while a remarkable 27 percent were for homicide.

The incidence of homicides committed by illegal aliens in some of the aforementioned five states examined by the GAO was particularly noteworthy. In Arizona, 68.57 out of every 100,000 illegal aliens statewide were actively serving prison time for homicide offenses, vs. a corresponding figure of 54.06 out of every 100,000 citizens and legal residents. In California, 97.2 out of every 100,000 illegal aliens statewide were in prison for homicide offenses, vs. 74.1 out of every 100,000 citizens and legal residents. And in New York, an estimated 168.75 out of every 100,000 illegal aliens statewide were incarcerated for homicide offenses, vs. 48.12 out of every 100,000 citizens and legal residents.

In sum, a total of approximately 5,400 illegal aliens in Arizona, California, Florida, New York, and Texas had been convicted of, and sentenced for, at least one murder each. In other words, at least 5,400 lives had been snuffed out by violent criminals who had no legal right whatsoever to even have set foot in the United States before they committed their heinous crimes.

Far too many illegal aliens who are arrested for various offenses, are subsequently set free to resume their criminal activities. Citing a Congressional Research Service report released in August 2012, FAIR reports: “[O]ver a 33-month period, between October 2008 and July 2011, more than 159,000 illegal aliens were arrested by local authorities and identified by the federal government as deportable but nevertheless released back onto the streets. Nearly one-sixth of those same individuals were subsequently again arrested for crimes.”

The Unique Case of Texas

Because Texas, as a border state, has been a primary destination for countless millions of illegal migrants over the years, it has been hit particularly hard by their criminal behavior. The Texas Department of Public Safety (TDPS) reports that between June 1, 2011 and December 31, 2016, more than 210,000 criminal aliens were booked into Texas jails, and that the Department of Homeland Security identified over 139,000 of them — or about two-thirds — as illegal aliens at the time of their most recent arrest. Over the course of their criminal careers, says DTPS, those 139,000 illegals had been charged with more than 559,000 criminal offenses, including: 1,132 homicides; 5,903 sexual assaults; 66,687 simple and aggravated assaults; 66,289 drug crimes; 16,304 burglaries; 682 kidnappings; 43,723 instances of obstructing police; 39,689 thefts; 3,677 robberies; and 8,375 weapons violations. Moreover, those 559,000 indictments ultimately resulted in about 251,000 convictions including: 464 for homicides; 2,674 for sexual assaults; 24,928 for simple and aggravated assaults; 32,818 for drug crimes; almost 8,000 for burglaries; 228 for kidnappings; 21,480 for instances of obstructing police; 17,956 for thefts; 1,861 for robberies; and 3,495 for weapons violations.

Between June 1, 2011, and November 30, 2021, some 356,000 criminal aliens were booked into state and local jails across Texas. Approximately 243,000 – or 73 percent – of them were in the U.S. illegally at that time. Those 243,000 were charged, cumulatively, with more than 401,000 criminal offenses, among which were 742 murders, 47,737 assaults, 7,524 burglaries, and more than 11,000 sex crimes.

According to the Center for immigration Studies (CIS), approximately 3.2375 out of every 100,000 illegals in Texas were convicted of homicide between 2012 and 2019 — a figure that was 29% higher than the 2.5125 per 100,000 rate among Texas’ overall population. Even more strikingly, 19.125 out of every 100,000 illegals in Texas were convicted of sexual assault during that same time frame – about double the 9.85 rate among all Texas residents. And CIS points out that even these pronounced imbalances understate the incidence of homicide and rape committed by illegals in Texas:

“There are two crucial caveats associated with [the figures cited above]. First, the ‘Illegal Conviction Rate’ is still underestimated. It is simply the number of illegal immigrant convictions identified by DHS plus the number of illegal immigrant convictions identified subsequently in prison, all divided by the total illegal immigrant population in Texas. More illegal immigrants could move out of the other/unknown category over time — especially in the most recent years….

“A second caveat is that comparisons of the types of crimes that illegal immigrants commit are inherently skewed. The longer people with unknown status are in custody, the more likely it is that Texas will correctly ascertain their immigration status. DHS and Texas DCJ [Department of Criminal Justice] have extensive time and incentive to investigate an individual’s immigration status when the crime is murder or sexual assault. Lesser offenses (e.g., larceny) carry shorter sentences and are a lower priority for deportation purposes, resulting in fewer unknown statuses moving to the ‘illegal immigrant identified in prison’ category over time. Therefore, the most serious crimes tend to generate the most accurate illegal immigrant conviction rates.” […]

CIS goes on to discuss how two particular studies grossly underestimated the incidence of illegal-alien crime:

“In February 2018, the Cato Institute’s Alex Nowrasteh released his analysis of 2015 DPS [Texas Department of Public Safety] data. He concluded that ‘the conviction and arrest rates for illegal immigrants were lower than those for native-born Americans.’ This conclusion was highlighted by the New York Times, Washington Post, NPR, and many other outlets.

“Nowrasteh’s error was to treat as native-born anyone who had not yet been categorized as a legal or illegal immigrant. He failed to understand the DPS ‘other/unknown’ category and the movement of illegal immigrants out of that category over time. […] ‘[N]ative-born’ is not a category verified by DPS. Native-born Americans are grouped with yet-to-be-identified immigrants in a catch-all category called ‘other/unknown’. The number of unknowns shrinks during incarceration as Texas updates the figures upon identification of an inmate’s immigration status. […]

“A 2020 study in the Proceedings of the National Academy of Sciences also claimed low rates of illegal immigrant crime based on Texas DPS data. Lead author Michael Light … found that felony arrest rates for illegal immigrants were half that of the ‘native-born’. His study has been favorably cited by the federal government in response to lawsuits filed by the state of Texas over illegal immigration.

“But Light makes the same mistake as Nowrasteh in treating illegals as fully identified by DHS at intake, even though DCJ will go on to identify more illegals who are initially placed in the DPS ‘other/unknown’ category. Unlike Nowrasteh, Light then relies on unverified claims made by arrestees about their citizenship and place of birth to both supplement the ‘legal’ arrest category and create a ‘native-born’ category. Not appreciating that arrestees of any claimed status could turn out to be DCJ-identified illegal immigrants, Light inadvertently places some illegals in his ‘legal’ or even ‘native-born’ categories.”

More Evidence Nationwide

In September 2018, The Hill reported that in a recent GAO study of America’s federal inmate population, criminal aliens constituted 21 percent of all those who served any time in prison between 2011 and 2016. Fully 91 percent of those federal criminal aliens were citizens of Mexico, Honduras, El Salvador, Dominican Republic, Colombia or Guatemala.

According to the United States Sentencing Commission, illegal aliens in Fiscal Year 2014 accounted for 36.7 precent percent of all those sentenced for federal crimes, 74.1 percent of all who received federal sentences for drug possession, and 16.9 percent of all federal drug-trafficking sentences.

In a 2015 National Review piece, U.S. Commission on Civil Rights member Peter Kirsanow reviewed statistics from the Government Accountability Office and Pew Research Center and reported that “approximately 2,430 illegal aliens are in prison just for homicide-related offenses” in California alone.

In a May 2016 story titled “Elusive Crime Wave Data Shows Frightening Toll of Illegal Immigrant Criminals,” Fox News reported that a trove of “local, state and federal statistics” which it had examined, “revealed a wildly disproportionate number of murderers, rapists and drug dealers are crossing into the U.S.”  Most notably, illegals constituted an estimated 13.6 percent of those who had been sentenced for all crimes committed nationwide in recent years, as well as 12 percent of those sentenced for murder, 20 percent of those sentenced for kidnapping, and 16 percent of those sentenced for drug trafficking. “The explosive figures show illegal immigrants are three times as likely to be convicted of murder as members of the general population and account for far more crimes than their 3.5-percent share of the U.S. population would suggest,” the Fox report added. Former Department of Justice attorney J. Christian Adams, for his part, described the trend as a “wave of staggering proportions.”

On May 2, 2017, The U.S. Department of Justice, in compliance with an order by President Trump, released data on the incarceration rates of illegal aliens. Of the 188,658 inmates who were in the federal prison system at that time, the number who were foreign-born was 45,493, of whom 41,554 were non-citizens. Immigration orders had been issued for more than half of those non-citizens — about 22,541 — while ICE was actively investigating another 13,886 inmates for possible removal.

A July 2018 GAO report stated that the 197,000 illegal-alien criminals who were incarcerated in federal prisons during the Fiscal Years 2011-2016, had been arrested, in aggregate, approximately 1.4 million times and charged with about 2 million offenses – or roughly 10 crimes apiece. The story was much the same vis-à-vis the 533,000 illegal-alien criminals who were housed in state and local prisons during the Fiscal Years 2010-2015: Cumulatively, they had been arrested about 3.5 million times and accused of approximately 5.5 million offenses – or slightly more than 10 crimes apiece.

In a 2018 study of inmates who had been housed in Arizona state prisons between January 1985 and June 2017, John Lott, president of the Crime Prevention Research Center, concluded that:

“Using newly released detailed data on all prisoners who entered the Arizona state prison from January 1985 through June 2017, we are able to separate non-U.S. citizens by whether they are illegal or legal residents.  Unlike other studies, these data do not rely on self-reporting of criminal backgrounds. Undocumented immigrants are at least 142% more likely to be convicted of a crime than other Arizonans. They also tend to commit more serious crimes and serve 10.5% longer sentences, more likely to be classified as dangerous, and 45% more likely to be gang members than U.S. citizens. […]

“While undocumented immigrants from 15 to 35 years of age make up slightly over two percent of the Arizona population, they make up about eight percent of the prison population. […] Young undocumented immigrants commit crime at twice the rate of young U.S. citizens. These undocumented immigrants also tend to commit more serious crimes.”

By contrast, Lott found that legal immigrants “were extremely law-abiding” and had lower crime rates than native-born state residents.

In a highly sophisticated study whose findings were released in 2019, FAIR examined the rate at which criminal illegal aliens were incarcerated in state and local correctional facilities in the 10 U.S. states whose illegal alien populations were the largest — Arizona, California, Florida, Nevada, New Jersey, New Mexico, New York, Oregon, Texas, and Washington. In aggregate, these 10 states accounted for 65% of the illegal population nationwide. To determine the rate at which illegals in those states were being incarcerated, FAIR analyzed prison data from: (a) the federal government’s State Criminal Alien Assistance Program (SCAAP); (b) other non-SCAAP figures from the federal government; and (c) the public records of state and local prisons, state corrections reports, and criminal-justice reports.

The FAIR study concluded that: (a) “in all SCAAP-reporting states along the Southern Border, and in SCAAP-reporting interior states that are preferred destinations for unlawful migrants, illegal aliens are incarcerated at a much higher rate than citizens and lawfully-present aliens”; and (b) “SCAAP data indicate that illegal aliens are typically at least three times as likely to be incarcerated [as] citizens and lawfully-present aliens.” The state-by-state breakdown was as follows: In California, the average illegal alien was statistically 231% more likely to be incarcerated than the average legal immigrant. The corresponding figures for the other 9 states showed that illegals were: 60% more likely to be incarcerated than the average legal immigrant in Texas; 78% more likely in Florida; 187% more likely in New York; 440% more likely in New Jersey; 301% more likely in Arizona; 248% more likely in Washington; 161% more likely in Nevada; 267% more likely in Oregon; and 42% more likely in New Mexico.

In December 2021, the U.S. Department of Justice (DOJ) issued a special report titled “Non-U.S. Citizens in the Federal Criminal Justice System, 1998-2018,” which  stated that of the roughly 41,000+ criminal aliens who had been prosecuted in federal courts nationwide in 2018, the vast majority—about 38,000—were in the United States illegally (and 74 percent were of Hispanic heritage). These figures were a far cry from the corresponding figures from 20 years earlier, in 1998, when scarcely 18,000 aliens – legal and illegal combined — had been prosecuted in federal courts.

The 2021 DOJ report further noted that a significant percentage of all illegal aliens who had been prosecuted in 2018 were repeat offenders: 12.5 percent had at least one prior federal or state criminal conviction, 18.5 percent had two-to-four prior convictions, and over 10 percent had five or more previous convictions. Many of these offenders were guilty of violent crimes like murder, rape, robbery, and kidnapping. Also prevalent were “drug offenses” – defined by the report as the “manufacture, import, export, distribution, and dispensing” of dangerous narcotics like methamphetamine.

Distressing as the foregoing numbers may be, they represent only the barest microcosm of the drug problem created by illegal aliens in the United States. As the Heritage Foundation notes: “The vast majority of crimes committed in this country are prosecuted at the local level, not the federal level. These federal numbers are only a fraction of the crimes committed by criminal aliens.”

ICE agents have federal jurisdiction to interrogate and arrest suspects about whom they have, as federal law puts it, “reasonable cause to suspect that grounds exist for denial of admissions to the United States,” within 100 miles of the US border on all sides. In Fiscal Year 2019, these agents arrested more than 143,000 people within the province of their authority. These included approximately 74,000 arrests for DUI; 67,000 arrests for drug offenses; 1,900 arrests for homicides; 1,600 arrests for kidnappings; 37,000 arrests for assaults; and 10,000 arrests for sex crimes.

In Fiscal Year 2020, the number of administrative arrests registered by ICE agents shrank to 103,603 – a reflection of the reduction in border-crossing traffic that resulted from the worldwide COVID-19 pandemic. At the time of their arrests, fully 90% of those 103,000+ arrestees already had criminal records consisting of a combined total of more than 374,000 previous convictions or charges – an average of approximately 4 per person.

In October 2020, The Hill stated that according to the Department of Homeland Security’s most recent “Alien Incarceration Report,” which was dated October 16, fully “94 percent of confirmed aliens” who were incarcerated at the federal level at Bureau of Prisons (BOP) and United States Marshals Service (USMS) facilities, were “unlawfully present in the United States.” “Additionally,” said The Hill, “70 percent of the 27,494 known or suspected aliens in BOP custody had been convicted of non-immigration-related crimes, as had 39 percent of the 23,580 known or suspected aliens in USMS custody.” But even these alarming figures represented only the tip of the iceberg, for approximately 90 percent of all incarcerated aliens are held at state and local jails and prisons, rather than at federal facilities.

The number of crimes committed by illegal aliens in the U.S. spiked dramatically in fiscal year 2021, under the open-borders policies of the Biden administration. Indeed, convictions for homicide or manslaughter increased by 1,900% from 2020 to 2021. The corresponding conviction increases for other serious offenses were: more than 400% for assault and domestic violence; 347% for DUI; and 453% for illegal possession or trafficking of drugs. All told, the number of “criminal noncitizens” apprehended by U.S. Customs and Border Protection officials was 341% higher in 2021 than in 2020.

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