The union representing teachers in the Fresno Unified School District is backing an Edison High math teacher accused of changing a student's grade. After conducting an investigation, FUSD superintendent Michael Hanson said on Monday that teacher Jeff Powell was the only person who could have changed the grade, even though he says someone else changed the "f" grade to an "A". Union representatives say the school district is making Powell a scapegoat and is calling for a grand jury investigation. Wednesday night, teachers showed up at the Fresno School District board meeting to voice their concerns about the allegations against Powell.