Five civil rights lawyers have sent a letter to Police Commissioner William J. Bratton saying that the recent questioning of protesters by detectives violated a federal consent decree and was not conducted by the proper New York Police Department division.

The questioning, in December, was of people arrested at protests after a decision by a Staten Island grand jury not to indict a police officer in the case of Eric Garner, who died last summer during an attempted arrest.

Eleven people who said they were questioned at Police Headquarters as they awaited their release told a reporter for The New York Times that they were removed one by one from holding cells and asked who had organized the demonstrations, who had participated in them and what forms of social media protesters used to keep track of them.

One man said he was asked whether he had attended meetings of a protest group. Another said detectives asked how they could receive messages from a Union Theological Seminary student email list discussing the demonstrations.