Atlanta Public Schools is preparing for annual, state-mandated Criterion-Referenced Competency Tests later this month.

This high stakes testing session is the first after an inquiry by the Georgia Bureau of Investigation suggested that at least 178 APS educators had cheated on the CRCT. The inquiry concluded the cheating had possibly gone on for years, up to and including the 2009 exam.

After the report's release, Superintendent Erroll Davis made a promise to Atlanta parents: "None of those implicated will be in the classroom when school starts this fall." Resign or be fired -- that was the message coming from Davis' office, in letters and in meetings. About 70 educators named in the report retired or quit.

Of the teachers that remain, educators with three or more years of experience have tenure. The district cannot terminate them without due process. The district might even be forced to offer contracts to accused teachers who haven't been let go by May 15.

Atlanta Public Schools spokesman Keith Bromery recently told CNN that about 100 educators who have been implicated in the investigation remain on the APS payroll, on paid administrative leave. The accused educators are costing the district $600,000 to $1 million a month.

APS is in the process of terminating all of the alleged cheating educators. The district "hopes to do all of these by the middle of May," Bromery told CNN.

Michael McGonigle, Georgia Association of Educators legal director, said that not all of the accused educators should face the severest penalty.

"There are plenty of folks who are innocent ... and have defenses, and we would expect exoneration or penalties less severe than terminations," he told the Atlanta Journal-Constitution.

Damany Lewis was the first and so far only educator to go through the entire process. Atlanta's school board fired him on March 21.

"We started with the most egregious cases," Bromery said, especially cases where there were confessions, such as Lewis'. Bromery said that as APS reviews the evidence, which resides in the Atlanta district attorney's office, officials build and send charge letters to the accused educator. In addition to a list of charges, the letters list evidence, potential witnesses and a hearing date in front of a tribunal.

The first round of 11 charge letters went out on March 2, including one to Lewis. According to his charge letter, Lewis admitted to state agents that he used a razor blade to open shrink-wrapped packages containing state-mandated testing booklets. He copied the contents, and then resealed the packages with a lighter after replacing the original exams. Lewis created answer sheets and distributed test materials to at least seven other teachers.

According to investigators, teachers at Parks Middle School, where Lewis worked, would hold "erasure parties." Teachers would try to improve test scores by correcting students' answer sheets.

It worked. In 2006, the percentage of Parks eighth-grade students who passed the math portion of the state's CRCT rose 62%.

But it was that improbable increase in achievement that led to Lewis' downfall. No one caught Lewis opening the test packages; and apparently, no one who received test booklets revealed that information before the GBI investigation.

The investigation began after the Atlanta Journal-Constitution found unlikely gains in test scores among some schools across the state. That led to an analysis of erased answers on test answer sheets, which revealed that a significant number of wrong answers had been changed to right ones. The extensive nature of the practice pointed not to students, but apparently to educators, including Lewis.

On March 14, Lewis faced a tribunal made up of several educators and overseen by a member of the State Bar of Georgia. Bromery said the tribunal could have recommended that the school board fire, suspend, reprimand or reinstate Lewis.

During this hearing, Lewis refused to answer the tribunal's question. "I don't want to say anything to further incriminate myself," Lewis said.

The president of the Atlanta Federation of Teachers, who represents 50 of the implicated educators, says that many of the teachers feel the process is unfair because administrators were asking their subordinates to cheat.

Lewis himself suggested that pressure from administrators caused the cheating. Lewis told the tribunal, "Teachers had nothing to do with the aura of fear and intimidation within the district."

At the end of Lewis' hearing, the tribunal recommended that he be fired, and one week later, Atlanta's school board did just that.