Trial of Partridge One

S3 E16: At school, Cindy Brown, the principal's daughter, is in a rush and asks Laurie to drop an envelope into the math teacher's mailbox for her. Just as Laurie is depositing the envelope, the math teacher grabs her arm -- the envelope contains a stolen copy of the math test. Laurie refuses to tell her where she got the test from; she is sure Cindy will tell her herself. The school is divided -- half of the kids carry signs reading "Expel Laurie;" others have signs to "Free Laurie." Laurie is ordered to appear for trial before a student court. Keith and Danny play "Perry Mason," acting as Laurie's defense. Laurie has confided to her mother that Cindy is the culprit -- being the principal's daughter, she is under too much pressure to get good grades. Shirley waits, but finally, right before the trial, she goes to see Cindy's father. He realizes that Cindy is the guilty one and Shirley convinces him not to stop the trial, but to give Cindy a chance to confess on her own, which she does at the student trial.