The sheer number of eraser marks on Alain Locke Elementary’s PSSA tests were telling signs of a scandal, but perhaps also a sign of the pressure that underfunded schools face when it comes to high-stakes testing.

That’s the argument made by Lolamarie Davis-O’Rourke, the West Philadelphia school’s former principal. On Wednesday, Pennsylvania Attorney General Kathleen Kane announced that a grand jury called for charges against Davis-O’Rourke for tampering with public records, forgery and criminal conspiracy. For three years, Davis-O’Rourke allegedly changed students answers, instructed teachers to help students with their tests and kept test booklets under her lock and key.

“This Office will continue to hold accountable corrupt school employees who put their own interests ahead of those of students in the classroom,” Kane said.

But Davis-O’Rourke told investigators she cheated out of fear for the school and her own job. She suspected Alain Locke would be shuttered or administrators fired if the school continued to perform under state standards.

A similar story echoes across the other cases of test cheating in Philadelphia. In 2014 alone, Kane charged educators from Cayuga Elementary in Hunting Park, former Communications Technical High School principal Barbara McCreery and former Bok Technical High School principal Arthur Melton. The crack-down on standardized test cheating is part of a statewide effort launched after a 2009 forensic report analyzed erasures on tests across the state. At 89 schools, the analysis found a disproportionate number of answers were corrected. In Philadelphia, more than 50 schools have undergone investigation.