Serving as a cautionary tale to Illinois school personnel, April Courtney, a former teacher in Lake County, was sentenced in July to 30 days in jail for failing to report a former colleague, Michael Vucic, in connection with an alleged sexual assault of a student.During the investigation of Vucic, who was later charged with numerous counts of sexual assault and related crimes involving a minor, authorities learned that Vucic told his co-worker and fellow teacher Courtney that he was having a sexual relationship with a …