The principal of an Omaha middle school criticized for her handling of reports against a teacher who was later convicted of sexually assaulting a student has resigned.

Prosecutors had considered bringing charges against principal Susan Colvin and other school administrators for not immediately reporting allegations of inappropriate behavior against Shad Knutson to police. Prosecutors decided against charging administrators when the school district changed its reporting policy.

Knutson faces up to 55 years in prison next month when he’s sentenced for abusing at least one student.

Colvin’s contract to continue as principal at Nathan Hale Middle School was recently renewed, but she announced Wednesday that she is resigning to take an administrative job at Omaha Public School District headquarters.