NEW YORK CITY—On Saturday night, Department of Homeland Security (DHS) agents entered a student residential building at Columbia University in uptown New York and detained Mahmoud Khalil, one of the lead negotiators on behalf of pro-Palestine protesters at 2024’s Gaza solidarity encampment. In a sweeping attack on the First Amendment, the Trump administration said this week it would begin revoking visas of “Hamas sympathizers,” specifically citing Columbia University students. The detention followed a two-day targeted online campaign against Khalil by pro-Israel groups and individuals, including Columbia’s high-profile pro-Israel professor, Shai Davidai. Khalil, an Algerian citizen of Palestinian origin and an American green-card holder, was detained by DHS officials around half past eight as he was entering the Columbia residential building he lives in. He was returning from an iftar, breaking the day-long fast observed by many Muslims during the month of Ramadan.

Khalil’s wife, who is eight months pregnant, was with him at the time. A statement by the pro-Palestine group Writers Against the War on Gaza (WAWOG) stated that he was “abducted and detained without the physical demonstration of a warrant or officially filed charges.” At the time of writing, Khalil is still being detained at a DHS facility in New Jersey, according to a database for U.S. Immigration and Customs Enforcement.

According to WAWOG, the DHS agents told Khalil that the U.S. Department of State had revoked his student visa. The group said this was “despite the fact that he has a green card, not a visa, and is a lawful permanent resident.” Khalil’s wife was unlocking the door to the building when “two plainclothes DHS agents forced their way in behind them.” They initially refused to identify themselves, she reported, but then threatened Khalil’s wife that if she remained with him, she would be detained too.

On Wednesday, Khalil was among the protesters at a sit-in at Milstein Library in Columbia University’s Barnard College, protesting the recent expulsion of three Barnard students over pro-Palestine activism. New York Police Department officers later arrested nine individuals from the same protest—the third round of arrests of pro-Palestine demonstrators on Columbia’s campuses in the past year.

Over the course of Thursday and Friday, several prominent pro-Israel groups and individuals published a series of tweets targeting Khalil, mentioning his presence at the sit-in on Wednesday and his history as a lead negotiator with Columbia in April 2024, and demanded that the Trump administration act strongly against him by revoking his visa and deporting him. They tagged President Donald Trump, Secretary of State Marco Rubio, and US Attorney General Pam Bondi.

Shai Davidai, a professor at Columbia Business School, who was suspended from entering Columbia’s Morningside campus in 2024 following allegations of misconduct against students and staff of the university, tweeted, “Illegally taking over a college in which you are not even enrolled and distributing terrorist propaganda should be a deportable offense, no? Because that’s what Mahmoud Khalil from @ColumbiaSJP did yesterday at @BarnardCollege”.

“Documenting Jew Hatred on Campus at Columbia U”—an account on X with more than 20,000 followers—tweeted, “Secretary Rubio (@SecRubio), please revoke Mahmoud Khalil's visa!” On March 6, Rubio had tweeted that “those who support designated terrorist organizations, including Hamas, threaten our national security” and that such “violators of U.S law—including international students—face visa denial or revocation, and deportation.”

A pro-Israel student protester at Columbia shared that Khalil was “known to have been on a foreign visa last year” before stating that he “recently helped illegally take over a library building”. Canary Mission posted against Khalil on their social media profiles with the caption “SUSPECTED FOREIGN NATIONAL ALERT”.

A post on Instagram by “Documenting Jew Hatred On Campus” and another account, “Jews In School,” referred to Khalil as a “foreign student agitator at Columbia University” and “the poster child for demonstrating that the Trump administration is serious about revoking visas of foreign students who support terrorism, foment hatred, and harass Jews.”

Saturday’s actions against Khalil also took place against the backdrop of the Trump administration’s decision to cancel around $400 million in federal grants and contracts to Columbia University. The White House has claimed that Columbia’s “failure to protect Jewish students from antisemitic harassment” was the reason for this move.

Columbia University recently set up an office that is secretly investigating its students for political statements about Israel, Drop Site News reported this week, and is requiring students to sign non-disclosure agreements to view the evidence being brought against them. On Friday evening, Columbia University’s Interim President Katrina Armstrong said that the university has reworked leadership structures to “more swiftly respond to incidents of antisemitism and discrimination on campus.”

Khalil, a graduate student at Columbia’s School of International and Public Affairs, had previously stated that he was accused by the university’s office of misconduct just weeks before his graduation in December 2024. “I have around 13 allegations against me, most of them are social media posts that I had nothing to do with,” he told the Associated Press in an article published on March 6.

After refusing to sign the nondisclosure agreement, Khalil reportedly said the university put a hold on his transcript and threatened to block him from graduating. But when he appealed the decision through a lawyer, he said, they eventually backed down.