Khalil’s arrest could have a chilling effect on on- and off-campus protests involving people who aren’t citizens, said Columbia University immigration law professor Elora Mukherjee. Already, she said, it had provoked panic and fear among immigrant students on campus.

Mahmoud Khalil's lawyer says he was arrested at his apartment near the university by agents who claimed they were acting on a State Department order to revoke his green card

The Trump administration is ratcheting up pressure on New York's Columbia University as it seeks to identify participants in pro-Palestinian demonstrations last year for possible deportation after immigration authorities detained a prominent Palestinian activist.