INDIANAPOLIS (AP) _ Indiana schools Superintendent Glenda Ritz says Department of Education staffers have found evidence of “manipulation'' in the state's school grading formula as part of a review stemming from a grade-changing scandal.
 
  DOE staffers are reviewing the grading formula after emails were published by The Associated Press showing former Superintendent Tony Bennett reworked the A-F system to elevate a charter school run by a top Republican donor from a “C'' to an “A.''
 
  Bennett resigned as Florida's schools chief last week. He denies giving special treatment to the Christel House Academy.
 
  Ritz declined Wednesday to give more details about the review. She told the state Board of Education a report could come as soon as Sept. 2. 
 
  Indiana's legislative leaders have launched their own investigation into the grading system.