PITTSFIELD, Mass. — David B. Harris of North Adams was arraigned on Wednesday in Berkshire Superior Court on single counts of possession of child pornography and dissemination of child pornography.

He had not-guilty pleas entered on his behalf before Judge Daniel Ford. He was released on $2,500 bail.

The 66-year-old former headmaster was arrested July 18, 2010, after police executed a search warrant at his Marion Avenue home. Police say they found USB drives with pornographic materials and a laptop with links to pornographic sites involving young boys. He is alleged to have disseminated child pornography on Jan. 24, 2010, and to be in possession of the materials on July 18. 

State police detectives assigned to the district attorney's office had been conducting a two months-long investigation, with assistance from both the Massachusetts and New York Internet Crimes Against Children task forces, as well as state police with the Middlesex district attorney's office and with the New York attorney general's office.

The Middlesex and New York police were involved because Harris was head of school for the Cambridge Montessori School, a private school for children from preschool to ninth grade, in Cambridge until his arrest and a trustee of one New York private school and former headmaster of another. He spent a decade as headmaster at Pine Cobble School in Williamstown until leaving in 2000.