How Military Trespass Charges Along the U.S.-Mexico Border Are Failing Migrants Who Didn’t Know They Were on Military Land

In Doña Ana County, New Mexico, a dirt road leads to the border wall along the U.S.-Mexico border. Photo by Paul Ratje for ProPublica and The Texas Tribune.

Our investigation began, as many do, with a spreadsheet. While analyzing federal court data, we noticed an unusual pattern: Within months of President Donald Trump’s inauguration in January 2025, prosecutors started filing obscure charges related to trespassing on military property—so many that 2025 saw more cases than the prior decade combined.

Nearly all of these cases originated along the U.S. southern border, where the White House designated large swaths of land as national defense areas last spring. This designation placed the land under military authority, allowing troops to play an unprecedented role in apprehending undocumented immigrants. Historically, federal soldiers are barred from enforcing domestic law, but this move circumvented that restriction. If caught in one of these zones, individuals could now be prosecuted for violating federal laws, including one enacted in 1909 to prevent espionage near arsenals.

Why Migrants Are Unknowingly Charged with Military Trespass

In our recent investigation, my co-reporters Perla Trevizo, Abe Streep, and Pratheek Rebala and I uncovered a critical flaw in these prosecutions: Many migrants did not realize the land they were crossing had been designated as military property. Judges have repeatedly ruled that ignorance of the land’s status can negate trespassing charges. Since April 2024, at least 4,700 immigrants charged with illegal entry have also faced military trespass charges; one individual waited over a month in jail before trial. Despite this, 60% of resolved cases resulted in dropped or dismissed trespass charges.

Yet prosecutors continue to file these charges. The full dataset used in our analysis is available on our GitHub page.

Military Trespass Cases Under the Trump Administration

Note: Counts reflect unique cases filed under 50:797 (“Penalty for violation of security regulations and orders”) and 18:1382 (“Entering military, naval, or Coast Guard property”). Source: Federal Justice Center’s Integrated Database. Chart by Agnel Philip/ProPublica.

As we visited courtrooms in West Texas and New Mexico and reviewed case records, the challenges of proving knowing trespass became evident. Some migrants could not read. At least one did not speak English or Spanish. The small signs demarcating military land are spaced far apart and easy to miss, and many arrests occurred far from these signs.

Government’s Stance and Unanswered Questions

A spokesperson for the Justice Department stated that these prosecutions have deterred unauthorized border crossings and cartel activity. Prosecutors have argued in court that illegally crossing the border is sufficient to establish criminal intent for military trespassing charges. However, senior officials in the U.S. attorney’s offices handling these cases declined repeated requests for interviews.

In November, Perla Trevizo, Abe Streep, and I embarked on a reporting trip throughout southern New