Substantial planning and premeditation is a legal term used to describe the level of planning and consideration that goes into a crime before it is committed. It is a requirement for a conviction of first-degree murder in many jurisdictions. It typically involves proof that the perpetrator was determined to commit the crime and took steps to plan out and carry out the crime. Generally, three types of substantial planning and premeditation are recognized: deliberation, preparation, and reflection. Deliberation involves the act of actually planning the crime, such as deciding which weapon to use or when and where to commit the crime. Preparation involves purchasing or gathering the material elements necessary to commit the crime, such as a weapon or tools. Reflection is the time the perpetrator spends reflecting on the decision to commit the crime, which is typically considered a sign of premeditation. The purpose of determining the level of premeditation is to help distinguish between intentional murder and other forms of homicide. If the perpetrator can be proven to have acted with premeditation, then the murder charge is typically upgraded to first-degree murder, which carries a longer punishment.