Two days before U.S. agents arrested Mahmoud Khalil, the Columbia University student and Palestinian activist asked his wife if she knew what to do if immigration agents came to their door.

Mahmoud Khalil, a 29-year-old legal resident of the United States, was arrested and detained by federal agents Sunday, after his green card was revoked by the Trump administration.

A prominent Palestinian activist who helped lead last spring's protests at Columbia University has been arrested by federal immigration agents.