Killing Mr. Griffin by Lois Duncan

Plot: Commencing at Del Norte High School of a small town called Alberseque, five students began to involve themselves in scheming and plotting of a very twisted plan which backfired on them. The scheme slowly evolved after many conflicts between the students and their English teacher, Mr. Griffin, for various reasons such as marks or dislike of his teaching methods. Mark, who had failed the course and deeply loathed Mr. Griffin, brainstormed to kidnap and "scare" the teacher with the help of his friends, Jeff and Betsy. In desperate need of a distraction or diversion for this plan, Mark told his friend, Dave to ask the smartest girl in the class, Susan (who liked Dave) for help; she was expected to arrange a conference with Mr. Griffin on the kidnapping day. Although Susan didn't want to, she agreed for Dave's sake. On the day, they waited anxiously for Mr. Griffin to come from the conference. When he approached, the students (except Susan) bagged his head and drove him to a secluded area. After they arrived there, the teenagers pressed the teacher to beg for a release, but he refused; out of anger, they dumped his heart medication and left afterwards. A few hours later, Susan called Dave with guilt to bring Mr. Griffin back, but too late --- the teacher already died of a heart attack when they came. They immediately drove back to school and notified their friends. Mark declared that they went too far and it was time to destroy any clues and hide the truth. Meanwhile, Mrs. Griffin notified the police, who assumed her husband deserted her. To add onto that, Mark persuaded Susan into lying to the police (she was supposed to be the last one to see the teacher) that Griffin left with another woman (lying he was still alive). To destroy all possible clues, the teenagers got rid of the car and buried the body. Just then, someone reported finding Griffin's medication (with his name). The police went to the spot, found the burial site, and dug up the body. Meanwhile,