Federal prosecutors on Thursday unsealed criminal charges against a first-grade New York City public school teacher who allegedly possessed and distributed hundreds of images and videos of child pornography. Christopher Ward, 37, was arrested on Wednesday and made an initial appearance before a federal magistrate on charges of receiving and distributing material containing child pornography, including files containing sexually explicit images of children, and possessing child pornography, including images and videos of prepubescent children and children who had not attained 12 years of age.