IOWA CITY, Iowa (AP) — A former Iowa fire academy manager has been charged with making up scores on tests that were used to improperly certify more than 1,700 firefighters and emergency responders.

A criminal complaint unsealed Wednesday alleges that former Fire Services Training Bureau certification manager John McPhee assigned “random scores to exams” without properly checking or correcting them.

The Iowa Department of Public Safety revealed that the bureau issued nearly 2,300 improper certifications to 1,706 firefighters and emergency personnel between 2012 and 2016. In each case, they were told that they had scored high enough to pass exams when they had not. Many departments require their firefighters to have certification, although it isn’t state-mandated.

Advocates for firefighters said Wednesday they fear the impact will be significant, undermining trust in their profession and requiring hundreds to retake tests they thought they’d passed long ago.

McPhee was arrested Tuesday on charges of misconduct in office and tampering with records. He didn’t immediately return a message left with his wife.