An antisemitic death threat made against a staff member of the Richmond Community School in Richmond, Michigan led to all the schools in the district closing last week.

Staff members found the handwritten death threat at the middle school after returning from holiday break last Tuesday. All the district’s schools were placed in lockdown as of that morning, Click on Detroit reported.

The death threat was described by police as a “complaint containing antisemitic remarks.” It contained a threat to an administrator of Richmond Community School along with their family. It was not directed at students or the whole school district, a district official said.

All schools in the district were closed last week while police investigated the incident. They reopened on Monday.

Richmond police called the investigation into the death threat “high priority.”

Superintendent Brian Walmsley announced that the district will press charges against the individual who wrote the letter, according to the news outlet

“[The] individual or individuals involved with leaving this threatening note [will] be prosecuted to the fullest extent of the law,” he said. “This is beyond comprehension that someone would threaten the safety of an employee and their family.”