This is a unit about teaching Claim Evidence Reasoning (CER) that can be expanded at the teacher's discretion to include a presentation and a paper that practices utilizing evidence, reasoning, and argument, or alternatively can also be collapsed into a mini-unit of just teaching Claim Evidence Reasoning (CER). This unit can also be used to teach the concept of Line of Reasoning for the AP Lang and AP Seminar Classes. It is structured as an investigation for students to explore the murder of a