Second-degree murder is a type of homicide that involves the intentional killing of another person without premeditation. This means that the act was not planned in advance, but the perpetrator acted with a reckless disregard for human life or with the intent to cause serious harm. In many jurisdictions, second-degree murder carries severe penalties, often resulting in significant prison time. It differs from first-degree murder, which involves premeditation, and from manslaughter, which may involve less culpable behavior. Legal definitions and consequences can vary by state or country, so it's important to understand local laws regarding homicide.