If you were waiting as I was for a firsthand account of test tampering at a D.C. public school, it came this week. A 42-year-old former principal says she was reduced to tears and hounded out of her job after she reported cheating at her Northeast Washington campus.

Adell Cothorne was hired in 2010 by then-D.C. schools chancellor Michelle A. Rhee to run the Crosby S. Noyes Education Campus. She had been an administrator in Baltimore and Montgomery counties. She was warmly welcomed by Wayne Ryan, the award-winning principal she replaced at Noyes. He was promoted to instructional superintendent and became her boss.

Cothorne was thrilled to land the Noyes job. Its test scores were among the best in the District, and it had been named a Blue Ribbon School of Excellence by the U.S. Education Department. But, just weeks into the school year, she couldn’t square those high test scores with what she says she saw in classrooms: mediocre teaching and faltering student performance. She began to worry that the scores were fraudulent.

D.C. Schools Chancellor Kaya Henderson, in a statement, said Cothorne’s lawsuit was based on “fictitious claims.” She said “there is no widespread cheating at DCPS.”

What is most striking about Cothorne’s account, which fits with testing data and previous reports about Ryan’s methods, is that no D.C. official with the power to investigate her complaints ever bothered to interview her about them. In the federal complaint, she identifies Josh Edelman and Hilary Darilek, then both prominent D.C. school officials, as the persons she called on Nov. 3 after accidentally discovering the apparent erasures.

D.C. schools spokeswoman Melissa Salmanowitz said Edelman and Darilek said they “never heard from Ms. Cothorne about these specific cheating allegations.” They said they were in frequent conversation with her but that she never told them about the erasing incident.

While what happened at Noyes could be seen as a he said, she said incident — and it is certainly possible that Cothorne misinterpreted what she saw — Henderson’s rejection of Cothorne’s account is in tune with her dismissal of other evidence of cheating at Noyes.

The school had 75 percent of its classrooms flagged by the testing company CTB/McGraw-Hill for unusual numbers of wrong-to-right erasures in 2008, followed by 81 percent in 2009 and 80 percent in 2010. At least five Noyes classrooms had wrong-to-right erasure rates of more than 10 per child, while the D.C. average was fewer than two.

University of North Carolina at Chapel Hill testing expert Gregory Cizek, who worked on the investigation of similar erasures in Atlanta, said only test tampering could produce so many changes from wrong answers to right ones.

At a time when test security was tightened system-wide, Cothorne changed the locks on the Noyes room where answer sheets were kept for tests in April 2011. The result: Scores dropped dramatically. The portion of Noyes students proficient in reading fell from 61 to 32 percent, and in math from 54 to 28 percent.