The document discusses three homicide schemes - common law, Pennsylvania, and the Model Penal Code. It provides definitions and examples of first-degree murder, second-degree murder, manslaughter, and related terms. It also summarizes two court cases - State v. Guthrie and the differing definitions of "deliberate and premeditated" from Schrader and Morrin. The last section discusses aggravating and mitigating circumstances in determining sentencing for first-degree murder under Arizona law.