As a legal matter, murder is defined differently by different jurisdictions and is divided into degrees according to the level of intent involved. Many common law jurisdictions require malice aforethought (or mens rea) to categorize a killing as murder, while civil-law systems tend to group all unjustified killings into one general crime of homicide. In most cases, the classification of a killing as murder or something less has significant consequences for the accused and can impact the charges and penalties applied.
In many instances, a person’s death will be classified as either first- or second-degree murder, or as manslaughter depending on whether they were acting in self-defense, during the commission of a felony, or in some other legally justifiable circumstances. Additionally, some states recognize a separate offense known as depraved heart murder that applies to killings committed with extreme recklessness or demonstrating a callous disregard for human life.
In addition, the length of time since a murder occurred can play a significant role in its investigation. As forensic technology advances, long-closed cold cases can be solved with the discovery of new evidence that wasn’t previously available to investigators. For example, a letter in a victim’s home can lead detectives to a witness who had been providing information about the killers to the authorities. As the detectives in this episode (Little Boy Lost, ep 11) found out, keeping detailed records of their investigations is more than just a memory aid. It can also be a vital tool in solving murders.