NYPD Commissioner Ray Kelly was shouted down by protesters during a talk at Brown University, and his planned lecture called "Proactive Policing in America's Biggest City" was canceled.
Students and activists protested Tuesday's lecture because of the department's stop-and-frisk policy and its surveillance of Muslims.
Many of them began shouting and chanting inside the lecture hall as the event began.
Brown officials asked protesters to allow Kelly to speak and reserve their comments until a question-and-answer session.
"We're asking you to stop stopping and frisking people!" shouted one protester.
When the ruckus continued, the hall was cleared.
Students opposed to Kelly's visit first petitioned the university to cancel the lecture, said Jenny Li, a Brown student who helped organize the protest.
When the university did not cancel the event, "we decided to cancel it for them," Yi said. She called the protest "a powerful demonstration of free speech."
Brown University President Christina Paxson said the protest "deprived the campus and the Providence community of an opportunity to hear and discuss important social issues."
"The conduct of disruptive members of the audience is indefensible and an affront both to civil democratic society and to the university's core values of dialogue and the free exchange of views," Paxson said in a statement.
Paxton said in a letter to the university community she will "convey my deepest regret" to Kelly and convene a campus forum "to discuss our values and expectations as a community."
A federal judge recently ruled the department's stop-and-frisk policy violated the civil rights of minorities. The city is appealing the decision."