The principal of the school inside Cook County jail returns to work today after a fraud allegation led to her banishment. The Cook County Sheriff’s Office had reacted swiftly banning the principal of the school inside the jail when she was accused of falsifying records. Now, Chicago Public Schools is saying those allegations are unfounded and asked the sheriff to let her back in. The sheriff’s office is complying, but noting the situation shows how difficult it is to educate inmates.