In addition, a DPS vendor -- identified as Norman Shy, 74, owner of Allstate Sales -- was charged. He is accused of being at the center of the criminal activity.
Authorities say the scheme basically boiled down to this: Shy paid bribes and kickbacks to principals so they would allow their schools to be charged for supplies that were never delivered.
Chairs. Teaching materials. Paper. The very things that students need to learn and schools need to function remained, frustratingly, out of reach.
But at the same time the school district cried poor, principals are accused of having lined their personal pockets.
"To hear this is just another slap in the face," DPS parent John Wills told CNN affiliate WDIV.
"We've been robbed blind."
Shy allegedly paid the principals a total of $900,000. In exchange, he received payments from the school system for $5 million, of which officials believe $2.7 million was fraudulent.
The bribery is said to have started in 2002 and continued until January 2015.
"The real victims in a case like this, of course, are the students and the families who attend Detroit Public Schools -- the teachers, the educators who really want to make a difference in the lives of Detroit Public School children," said U.S. Attorney for the Eastern District of Michigan Barbara McQuade.
"A case like this is a real punch in the gut for those who are trying to do the right thing."
'Cannot overstate the outrage'
Of the 13 Detroit Public School officials charged, seven are former school principals; six are still working in that capacity. One of the former principals is now an assistant superintendent.
Included among those implicated is Ronald Alexander, principal of Spain Elementary-Middle School. His alleged involvement is notable because the school was recently tapped by Ellen DeGeneres
to receive half a million dollars in donations.
The talk show host announced that the Lowe's chain of home-improvement stores would donate $500,000 toward repairing the school, including $50,000 in new computers and a $100 Visa gift card to every teacher and staff member.
CNN toured Spain Elementary-Middle School
before DeGeneres stepped in, and to say the conditions there were lacking is an understatement.
Children played in the hallway because the gym floor was warped from rain damage and torn up on one side. Clouds of steam poured into the playground, making that area unsafe, too.
One teacher complained of mice, roaches and bedbugs. The school nurse considered the impact on students' health, saying dry air in the building and changes in temperature were making the students sick.
"I cannot overstate the outrage that I feel about the conduct that these DPS employees engaged in that led to these charges," Detroit Public Schools Transition Manager Judge Steven Rhodes said in a statement Tuesday, after the charges against the principals were made public.
"This behavior is absolutely unacceptable and will never be tolerated. Illegal behavior of any kind will result in immediate suspension and possible termination."
He announced a series of immediate changes to help ensure that such conduct is not repeated. They include the suspension of all purchases by individual schools, a review of all school-based vendor contracts and the recruitment of an independent auditor.
Detroit Public Schools suspended business with Shy and all of his companies.
'Easy to get caught'
McQuade recognized during her news conference that accusations of public corruption never come at a good time. Still, it's coming at a particularly bad time for Detroit Public Schools.
In addition to dealing with poor conditions at its schools, the system is hundreds of millions of dollars in debt and being sued by the union.
This month, there were threats of a sickout. Although it didn't materialize
, a sickout is a way for teachers to protest working conditions, dilapidated facilities and inadequate funding.
Embattled Gov. Rick Snyder, who is also dealing with the fallout from the Flint water crisis, said in his State of the State address that the city's schools are in a crisis.
The school system was previously under the supervision of an emergency manager appointed by Snyder, Darnell Earley.
Earley, who was also Flint's emergency manager from 2013 to 2015, resigned last month.
McQuade said Tuesday that if there is a message to be taken from the kickback case, she hopes it will be one of accountability.
"It may seem easy to take a bribe but, I'll tell you what, it's also easy to get caught," she said. "And we will catch you."