Our reporting, like many other jobs, started with a spreadsheet. As I was analyzing federal court data, I noticed something strange. Within months of President Donald Trump’s inauguration in January 2025, prosecutors began filing murky charges related to trespassing on military land. In fact, the number of cases was so high that more lawsuits were filed in 2025 than in the previous decade.
Nearly all of these charges stem from incidents along the U.S. southern border, where the White House designated vast swaths of land as a national defense zone last spring. By placing them under military authority, the military was able to play an unprecedented role in apprehending illegal immigrants. Federal soldiers are generally prohibited from enforcing laws within the country. If you’re caught in one of these zones, the government could also prosecute you for violating a 1909 federal law designed to keep spies out of the arsenal.
In a recent investigative report, my co-writers Perla Treviso, Abe Streep, Prasik Lebara and I dug into what experts say are serious flaws plaguing these prosecutions, leaving people vulnerable to crimes they didn’t commit. That is, the migrants were unaware that the land they were crossing was now in the possession of the military. And many judges have ruled that if you did not know you were on military land, you are not guilty of trespassing on that land.
Since last April, at least 4,700 immigrants already charged with illegal entry have been found facing these military trespass charges. At least one had to wait more than a month in jail before being tried. Most of the claims were not applied. In fact, we found that trespassing charges were dropped or dismissed in 60% of resolved cases. However, prosecutors continued to file charges.
Download the complete data used for analysis from the GitHub page.
Military trespass incidents have increased rapidly under the Trump administration.
Note: Counts are for special cases charged under 50:797 (“Penalties for Violation of Safety Regulations and Orders”) and 18:1382 (“Entry into Military, Naval or Coast Guard Premises”).
Source: Federal Judicial Center Consolidated Database.
As we visited courtrooms in West Texas and New Mexico and pored over case files, it became clear how difficult it is to prove that someone intentionally trespassed on military land. Some people couldn’t read. At least one person spoke neither English nor Spanish. The small signs were placed far apart and easy to miss, and many migrants were arrested far from the signs.
A Justice Department spokesperson said prosecutors had thwarted unauthorized border crossings and cartel activity. Prosecutors argued in court that illegal crossing was sufficient to prove military intent to commit trespassing. Senior officials at the U.S. Attorney’s Office, which handles trespassing cases, declined repeated requests for interviews.
In November, Perla, Abe, and I decided to cover all of southern New Mexico and west Texas to see for ourselves what information we could glean about where the zones are and how they are marked.
Abe and I arranged a ride with Doña Ana County Sheriff Kim Stewart. The New Mexico Sheriff’s Office shares jurisdiction with the Border Patrol and military in one of the zones. The sergeant in her office drove us along a dirt road parallel to the border, pointing to a 12-by-18-inch red and white sign across from the fence. She said her office has not received specific information about where the boundaries of the military zone are. All they had were signs. Even in broad daylight, it was difficult to read unless you got within a few feet of it.
These small signs are placed throughout the Defense Area, but their size and placement are often difficult to understand. Paul Lache of ProPublica and the Texas Tribune
On another outing in New Mexico, this time with photographer Paul Lache, we went to a location in Sunland Park where Lache had previously taken photos of the border fence. This two-acre unpaved lot was located less than a mile from a residential neighborhood and a popular Italian restaurant. From the compound, more red and white signs could be seen along the nearby Border Road.
As we were taking photos, a pickup truck with Border Patrol livery approached. I was surprised to see that there were two Army soldiers inside, rather than Border Patrol personnel. The soldier in the passenger seat pointed to a sign along the border road and told me not to drive past it. He said the border road was part of the defense area, but the compound where we were standing was not.
The next day, Perla and I returned to the same location. This time, Border Patrol agents drove up. The compound was part of the defense area, he told us. When I pointed out that I had been given contradictory information the day before, the official said he had been told by the military that no one was allowed in the area. we set off. (An Army spokesperson said the base responsible for the New Mexico defense area issued a map in December, but that map did not include the site.)
Interactions with border guards and the military have so far only added to our confusion about these areas. Later that day, Perla and I drove south to the border fence along the Rio Grande near Tornillo, Texas. We saw a Border Guard van near the fence gate. I thought I would ask where the field of defense is. Before we could do that, another Border Patrol van came up to us. Soldiers emerged from both vehicles, including one carrying a rifle on his shoulder. Another soldier said there was “no freedom to discuss” the exact location of the national defense area.
The answer puzzled us. We asked him how we would know if we were trespassing. he shrugged. (Spokespeople for U.S. Customs and Border Protection and the Department of Defense did not directly respond to questions about these interactions.)
Perla and I thought as we headed back to our rented SUV. As a reporter who makes a living investigating things, if we can’t get clear answers about where these military zones are, how did the government expect people crossing the border to behave better?
In the four months between our reporting trip and the release of the findings on March 16, the government continued to file charges of military trespass in more than 1,300 cases. It also established new military zones in Arizona, California, and Texas.
