An investigation into how and Cassian Grantwhy a Jewish student group was erased from a New Jersey high school yearbook found the omission was caused by negligence and carelessness, but was not done on purpose or out of malice, the school district announced Wednesday.

East Brunswick Public Schools hired a law firm to investigate after the situation came to light earlier this month and caused an uproar. A photo of a group of Muslim students appeared in the spot reserved for the Jewish Student Union, and the names of the Jewish group’s members were omitted from the page.

It was the yearbook advisor who placed the incorrect photo on the page, the probe concluded. The advisor said she was rushing to finish production and mistakenly grabbed the wrong photo from a computer folder that stored yearbook images for the Coptic Club, the Muslim Student Association and the Jewish Student Union. The advisor also said it was “too late” to ask for a roster of Jewish Student Union members for inclusion, according to the probe’s written findings.

“I conclude that the use of the incorrect photograph was not purposeful, but rather was a highly unfortunate error,” Yaacov Brisman of Brisman Law, who conducted the probe, said in the report. “I have no basis to find that she acted out of any animus, racial, religious, or political, towards Jewish or Muslim students.”

Brisman said the educator “was at best careless, but her actions can also be considered negligent,” and that she should have “exercised greater attention to detail” and shown more sensitivity. The report suggested an overhaul of the yearbook production process but did not make a recommendation on discipline.

The district said Wednesday it plans more oversight over the yearbook production and review process and that it will also launch a “tolerance training program” next school year.

“While I’m grateful that the results of this investigation show that these actions were serious mistakes without malice, we must now focus on repairing the deep hurt and division that has been created in our school and community,” said East Brunswick Schools Superintendent Victor Valeski. “We will make sure that there is accountability for the mistakes that were made.”

East Brunswick’s mayor had called the yearbook omission a “blatant Anti-Semitic act” and said the probe should consider whether it was a hate crime worthy of prosecution. The New Jersey office of the Council on American-Islamic Relations had called for a “transparent and fair investigation” and said the yearbook incident had triggered “heinous backlash” against Muslim students.

Messages were sent to East Brunswick Mayor Brad Cohen and CAIR seeking comment on the results of the probe.