BOSTON (AP) — Minority students at three prestigious law schools say they want to delay final exams because they’ve been busy protesting grand jury decisions in the deaths of unarmed black men at the hands of white police officers in New York City and Ferguson, Missouri, and haven’t had time to study.

Student groups at Harvard Law School, Georgetown University Law Center and Columbia Law School say demonstrations and rallies over the Eric Garner and Michael Brown cases have prevented many students from adequately preparing for exams.

Cities across the country have seen large-scale demonstrations since grand juries in both cases recently decided not to indict the police officers in the men’s deaths. A medical examiner says Garner, who had asthma, died after being placed in a chokehold by an officer on Staten Island. Brown was shot by an officer in a St. Louis suburb.

At Harvard Law School, a coalition of student groups representing Asian, black, Native American and other minority students says many students have been compelled to take action because the “national tragedy” implicated a judicial system they had chosen to join by studying law. They criticize administrators for largely staying on the sidelines.

“We led rallies, held vigils, and published an oped. You were silent on this issue,” the coalition wrote in a letter issued over the weekend. “We petitioned the government, served as legal observers, created spaces of solidarity, drafted model legislation, and marched through the streets of Boston and Cambridge.”

Harvard Law School Dean Martha Minow, with Yale Law School Dean Robert Post, penned an op-ed that ran in the Boston Globe on Tuesday. In it she called for criminal justice system reforms.

Minow also is hosting a Wednesday campus discussion in which faculty and students are expected to participate.

University officials at Harvard, Georgetown and Columbia have said students can petition to have their exams rescheduled and the requests will be considered individually, a process their policies already provided.

Columbia and Harvard also are offering students special sessions with trauma counselors, mental health professionals and professors to talk about the lack of indictments in the Brown and Garner cases in the coming days.

“Our practice of individualized consideration, among other things, allows us to connect with students and provide them the support they need when they are suffering trauma severe enough to warrant deferral,” wrote Ellen Cosgrove, dean of students at Harvard Law.

Officials at the three schools did not specify how many students have sought or been granted the exam exceptions. And none of the schools has issued a general postponement of end-of-semester exams.

But the Harvard Law School coalition, on its website, notes that a campus-wide delay is not without precedent: In 1970, the faculty voted to delay all exams in response to demands by students participating in anti-war protests.

At Columbia, officials urged students to remain focused on the serious issues the cases raise.

“Focusing on routine matters such as exam schedules ... diverts attention away from the real issue that should be examined now: how to ensure a criminal justice system that protects fairness, due process, and equality,” the school said in a statement.