In a letter to New York City Police Commissioner Dermot Shea, the president of the New York City chapter of the National Lawyers Guild on Sunday demanded discipline for the NYPD officers who searched and detained NLG legal observers at a protest Thursday in the Bronx.

During the protest against police brutality in Mott Haven, nine legal observers wearing neon green hats marked “National Lawyers Guild Legal Observer” were restrained with zip-tie cuffs and prevented from doing their constitutionally protected work, NLG-NYC President Andy Izenson wrote in the letter.