Claire Shipman, the university’s acting president, noted the absence of Mahmoud Khalil, a graduate who continues to be detained by immigration authorities.

The head of Columbia University alluded to the detention of Palestinian activist Mahmoud Khalil during a commencement speech Wednesday that drew loud boos and chants of “free Palestine” from graduatin

Claire Shipman, acting Columbia University president, faced widespread booing from students during a second day of commencement ceremonies. Shipman acknowledged the absence of graduate student Mahmoud Khalil,