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Federal Prosecutions of Illegal Immigrants

Despite claims from the Trump administration that immigrants are more likely to commit crimes, the size of the non-citizen federal prison population reflects the Bush and Obama administrations’ enforcement priorities to prosecute more immigration offenses in criminal court, rather than giving any insight into immigrant criminality. Previously, we have studied existing data on non-citizens in federal prison and in state and local corrections facilities to explore this topic. Now, a review of U.S. government prosecution data refutes the administration’s claims, showing that the increase in prosecutions against immigration offenders to deter illegal immigration correlates with increased convictions and sentencing of non-citizens, meaning that an administration’s prosecution of immigration offenses not necessarily inherent immigrant criminality is a key driver of the non-citizen population size in U.S. federal prisons.

Data from the Offices of the United States Attorneys shows that the number of criminal cases, defendants, and convictions for immigration-related offenses increased after significant policy changes introduced in 2005. As Figure 1 shows, the number of cases filed and number of defendants followed the same trajectory, growing by 65 percent and 58 percent respectively between 2007 and 2010 before decreasing through 2016. Most importantly, the number of convictions kept pace with the growth in the number of cases and defendants, meaning almost all cases ended with the defendants pleading or found guilty for these violations.

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Source: Offices of the United States Attorneys

The rise in prosecutions followed the introduction of Operation Streamline, which the Department of Homeland Security introduced in 2005 to deter illegal border crossing by referring significantly more illegal border crossing cases to the Department of Justice for criminal immigration prosecution. The decline in cases filed after 2010 reflects multiple factors, ranging from the Obama administration’s efforts to target more serious criminals entering the United States after 2014 and the significant decline in border apprehensions over the last decade along U.S.-border due to a fall in Mexican immigration and improved border enforcement measures.

The central role that Operation Streamline played in shaping the federal prison population emerges more clearly when examining the leading charges for these convictions, which are largely for illegal border crossing violations. As Figure 2 shows, 2014 data from the Transactional Records Access Clearinghouse (TRAC) finds that illegal entry convictions, a federal misdemeanor under Section 1325 of the Immigration and Nationality Act (INA), were the largest category between 2004 and 2013, which aligned with Operation Streamline’s adoption and expansion. The chart also shows that illegal re-entry convictions, a federal felony under Section 1326 of the INA, is the second largest immigration violation category, reinforcing this picture.z

Source: TRAC

Analysis of more recent government data suggests that this trend continues to persist even as immigration convictions have dropped in the last few years. A January 2018 TRAC report noted that 576 of the 4,758 convictions in November 2017 resulted in a prison sentence of over a year, suggesting that the majority of these violations were relatively minor ones, which could include illegal entry. Within the 576 convictions resulting in imprisonments over a year, 77 percent were for illegal re-entry violations.

TRAC data also shows that federal district courts along the U.S.-Mexico border issue a significant number of immigration-related convictions, demonstrating how prosecutions and convictions of illegal border crossing offenses grew in the federal courts system under Operation Streamline. In November 2017, the judicial districts with the highest number of immigration convictions were the Western District of Texas (1,231 convictions), Arizona (1,066 convictions), and the Southern District of Texas (872 convictions). As Figure 3 shows, judicial districts on the border also have ranked highest in the number of convictions with sentences lasting over a year, with the Southern and Western Districts of Texas appearing in the top three judicial districts in 2017, 2016, and 2012.

Figure 3: Top 10 Judicial Districts by Immigration Convictions with Imprisonments Lasting Over a Year

Source: TRAC
Judicial DistrictConvictions
(November 2017)
Top 10 Rank
(November 2016)
Top 10 Rank
(November 2012)
Texas Southern111
Texas Western223
California Southern344
New Mexico557
Texas Northern668
California Central8135
Florida Middle91114
Puerto Rico102530

Finally, Bureau of Justice Statistics data shows that immigration offenses became the leading sentencing violation for undocumented immigrants between 2005 and 2014, meaning that these courts were sending significantly more non-citizens to federal prison after being prosecuted and convicted for illegal entry and illegal re-entry under Operation Streamline, as opposed to other federal crimes. As Figure 4 shows, undocumented immigrants sentenced for immigration offenses were the majority of the undocumented sentenced population, which remained a small percentage of the overall federal prison population through 2005. After the program’s introduction, these offenders remained the largest group of the total undocumented population, which expanded significantly after 2005 as more individuals were likely being prosecuted through the Operation Streamline.

Source: Bureau of Justice Statistics

The overall impact of Operation Streamline was to move immigrants away from administrative removal proceedings (or simply returned across the border) and into the criminal justice system. Until 2005, U.S. Customs and Border Protection (CBP) agents would mostly use administrative removal procedures or the civil immigration system to remove illegal entrants. Under Streamline, CBP agents refer individuals entering the United States illegally to the United States Attorney’s Offices for fast-track criminal prosecutions in federal district courts, with some courts processing 70 prosecutions per day. The Obama administration expanded the program, which it incorporated into a broader border security measure known as the Consequence Delivery System, which had other measures aimed at increasing the consequences of illegal entry to deter individuals from returning to the United States after deportation. Given that these prosecutions led to a large number of convictions and prison sentences for non-citizens who committed immigration offenses, the program’s growth guaranteed that these individuals entered federal prisons in greater numbers.

This last point is critical to understanding why non-citizens currently make up a significant portion of the federal prison population. In contrast to the Trump administration’s claims that immigrants exhibit high levels of criminality and, as a result, enter federal prison in higher numbers this data shows that the conscious decision to shift illegal entrants from administrative to criminal proceedings to deter illegal entries into the United States directly impacted the number of non-citizens sent to federal prison. Contrary to the statements of the Trump administration, the higher number of immigrants in federal prison is not proof of higher rates of overall criminality among immigrants, but ultimately is a product of a decade of more prosecutions of immigrants for illegal immigration.