More than three years after a state investigation began into unexplained rises in student test scores, former Atlanta Public Schools superintendent Beverly Hall was indicted along with 34 others on racketeering charges. NBC's Brian Williams reports.

A grand jury indicted a former superintendent and more than 30 other educators Friday in one of the nation's largest cheating scandals that rocked Atlanta's public schools.

The indictment named the former Superintendent Beverly Hall as well as several high-level administrators, principals and teachers. Hall faces charges including racketeering, false statements and theft. She retired just days before the 2011 probe was released, and has previously denied the allegations.

A state investigation in 2011 found cheating by nearly 180 educators in 44 Atlanta schools. Educators gave answers to students or changed answers on tests after they were turned in, investigators said. Teachers who tried to report it faced retaliation, creating a culture of "fear and intimidation" in the district.

The cheating came to light after The Atlanta Journal-Constitution reported that some scores were statistically improbable.

The criminal investigation lasted 21 months and the allegations dated back to 2005.

Most of the 178 educators named in a special investigators' report resigned, retired, did not have their contracts renewed or appealed their dismissals and lost. Twenty-one educators have been reinstated and three await hearings to appeal their dismissals, said Atlanta Public Schools spokesman Stephen Alford.

The tests were the key measure the state used to determine whether it met the federal No Child Left Behind law. Schools with good test scores get extra federal dollars to spend in the classroom or on teacher bonuses.

Georgia last year was granted a waiver from the federal law, which allowed schools to count a host of measures in addition to standardized tests.

State schools Superintendent John Barge said last year he believes the state's new accountability system will remove the pressure to cheat on standardized tests because it won't be the sole way the state determines student growth. The pressure was part of what some educators in Atlanta Public Schools blamed for their cheating.

Alford, the schools spokesman, said the district was moving on from the scandal.