On Tuesday, four senior Homeland Security Investigations (HSI) agents testified before the U.S. District Court for the District of Massachusetts in a case challenging the Trump administration’s targeting of noncitizens on the basis of their pro-Palestinian activism. As Politico reported, the agents—including those who supervised the teams responsible for apprehending Mahmoud Khalil and Tufts University student Rümeysa Öztürk—said they received “top-down” instructions to detain the Palestinian rights activists. One HSI agent testified that the request “was not something that I had much experience with, if any.”

In a July 16 filing obtained by the Prospect, attorneys representing the plaintiffs argued the agents “each testified as to their understanding that a decision was made at the highest levels of government to prioritize the arrests of the targeted non-citizens, but not a single one of them knew why.”

HSI has broad discretion over which federal crimes it investigates, but Trump’s return to office has marked a notable shift in HSI’s priorities, as is true across numerous federal law enforcement agencies. “I’m still in touch with heads of federal agencies … and they are just flabbergasted that they’re all being tasked to become border agents and immigration agents, and they haven’t been trained for that,” a former top official at the Drug Enforcement Administration (DEA) told the Prospect. “They’re keeping their heads down because this regime [will] fire you if you express any opposition.” Agencies dragooned into immigration enforcement include the DEA, Federal Bureau of Investigation, Bureau of Alcohol, Tobacco, and Firearms, Fish and Wildlife Service, Postal Inspection Service, and the Department of Agriculture’s Forest Service.

The First Amendment applies to all persons in the U.S., regardless of citizenship status. Opposing American foreign-policy interests is not a crime, but as the former top DEA official observed, the Trump administration has been seeking to deport political dissidents who are “here on a green card or visa” for exercising their constitutional rights.