With back to school right around the corner, the majority of Chicago schools’ 43,000 employees have cleared background re-checks, the district said Sunday. Still, 266 employees have not been cleared, and 57 of those employees are teachers.

As of Sunday, 98 percent of staff had been cleared to return to school. The employees who were not cleared were flagged because of something on their record suggesting a charge related to sexual misconduct, violence, or dangerous criminal activity. 

“[Chicago Public Schools] will be conducting thorough investigations in all of these instances to better understand the circumstances of each unique case,” district spokesman Michael Passman said in a statement.

An additional 245 employees have not submitted their fingerprints to the district. They also are not permitted to teach.

Earlier this week, the district’s background checks temporarily snagged hundreds of employees. A Chicago Teachers Union spokeswoman said on Friday that the union had received dozens of calls from alarmed teachers who were not yet cleared to return to school, including teachers who had been arrested for a 2016 downtown protest of pension cuts. On Sunday, the district said teachers who had been flagged for charges related to protest or political activity were cleared.

In June, the Chicago Tribune released a series of stories revealing big gaps in how the district handled complaints of sexual misconduct against students by teachers, coaches, and other adults who work in schools. Scrambling to address systemic lapses, the district moved quickly to implement a series of new policies, including requiring all employees, vendors, and volunteers to complete background re-checks before the beginning of the new school year.

Chicago schools’ Chief Education Officer Janice Jackson said in an e-mailed letter to parents Sunday that the overwhelming majority of adults in schools are committed to keeping children safe, but “it’s the small minority of employees whose records require deeper inquiry (who) will receive the thorough review they deserve.”

The district also required all employees to re-submit fingerprints before the start of the school year. The district said that if employees go to work without having submitted their fingerprints, they will be disqualified from future employment with the district.

Former Assistant U.S. Attorney and Illinois Executive Inspector General Maggie Hickey has been hired by the district to review how it handles sexual misconduct cases. CPS released her preliminary findings in early August. “By conducting the background check refresh,” she wrote, “CPS has made significant progress toward ensuring that all adults working in schools have been background checked under uniform, rigorous standards.”