Which crime type must the author be guilty of for someone to be an accessory to it?

The correct answer focuses on specific serious offenses where the concept of "accessory" is particularly relevant and significant in the legal context. An accessory is someone who assists or helps another person commit a crime but is not the principal perpetrator.

For crimes such as murder, treason, parricide, or infanticide, the law considers the role of an accessory very seriously due to the severe nature of these offenses. Accessory laws are designed to hold individuals accountable who may provide support, encouragement, or aid in the commission of these crimes, even if they do not physically carry out the criminal act themselves.

In contrast, while robbery, theft, and assault are also offenses where one could be an accessory, the gravity of these crimes does not carry the same implications in terms of the accessory's legal accountability. The connection to more heinous crimes is what makes the distinction relevant in legal contexts involving accessories. Therefore, it is essential to understand that the severity of the crime often dictates the complexity and implications of being classified as an accessory.