The move, which will include tougher background checks and expanding training, was announced a day after a third employee at Needham Public Schools was arrested on child pornography charges.

A Massachusetts elementary school worker has been charged with possession of child pornography, becoming the third employee from his school district to face such a charge in the last four months.

Another Needham Public Schools has been arrested over allegations of having child sex abuse images, officials said Tuesday, prompting the Massachusetts district’s superintendent to discuss the possibility of changing district policy for increased oversight of its staff and contractors.