First-degree murder is a serious crime that involves intentionally killing someone with premeditation, meaning the person planned the act beforehand. This type of murder shows a clear intent to cause harm and is often considered the most severe form of homicide. The law treats it harshly because it reflects a deliberate choice to take another person's life. In many legal systems, a conviction for first-degree murder can lead to severe penalties, including long prison sentences or even the death penalty in some places. The prosecution must prove that the accused had a motive and a clear plan, distinguishing it from other types of murder, like second-degree murder or manslaughter.