Another student alerted a substitute teacher of the sexual relationships, court documents show. The teacher then passed the information along to DePaul.
When DePaul heard of the allegations, she was "in denial" and tried to "protect the teachers," according to court documents. She also allegedly told a witness who came forward to delete evidence from his phone. Prosecutors dropped a charge of suppressing evidence.
Superior Court Judge Thomas A. Brown Jr. declined DePaul's request to prevent the guilty plea from being used against her in a potential civil suit.
"This is very disturbing," he told DePaul after sentencing her in a Camden County courtroom to one year of probation. "There is a bond between teachers and principals and students. It's a sacred bond, a bond of trust. You have violated that bond."
None of the defendants showed any emotion Monday, saying only "yes, sir" or "no, sir."
Prosecutor Warren Faulk said he was pleased with the outcomes, telling reporters that his main goal was to ensure that the three "not hold public office" in the future. He added that the victims' families were satisfied with the agreements.
Logandro and Michielli each agreed to 30 days of detention - which could be house arrest - and will be sentenced to one to five years of probation in March. Each admitted Monday that he "cultivated and engaged in an improper relationship" with a student.
As part of their plea agreements, more serious charges of criminal sexual contact and endangering the welfare of children were dropped. A charge of sexual assault against Michielli also was dropped.
In a letter to the Black Horse Pike Regional School District community, Superintendent John F. Golden wrote Monday that the "foundation" of the district's "safe and secure learning environment" had been "jeopardized."
"We, as a community, have a shared commitment to doing what is best for students so that they may be prepared for tomorrow's challenges," he continued.
"The faculty and staff understand that it is not acceptable to ignore that commitment, nor will actions counter to that commitment be tolerated."
Two other defendants in the case still face trial.
Teacher Nick Martinelli, 28, of Cherry Hill, has been charged with official misconduct for engaging in inappropriate sexual activity with a female student. Former vice principal Jernee Kollock, 39, of Williamstown, is charged with official misconduct.
Contact Andrew Seidman at 856-779-3846, firstname.lastname@example.org or @AndrewSeidman on Twitter.