Season 4: Episode 20 - Something's Rotten in Redmund

Something's Rotten in Redmund: The body of a young and popular English teacher is found bludgeoned to death on the Redmund High School campus, making everyone from the students to the janitorial staff a suspect. While Jane snoops around the school hoping to uncover who might have reason to kill a teacher, Rigsby and Van Pelt investigate the victim’s life away from his job. When a student admits to having seen the victim solicit a prostitute and the CBI finds drugs in his car, it looks like the beloved teacher might not have been as virtuous as previously suspected.