This episode is brought to you by Aj+. Killing another person is always wrong, right? It's in every country's legal doctrine, every major religion, even going back as far as 2000 BC, where the Sumerian code punishes any man who kills another man. But despite universal opposition to homicide, there have been situations where killing someone else is justified. So when is homicide legal? Well, first and foremost, the legality of homicide depends largely on the difference between what murder is and isn't. Murder is typically defined by several characteristics: it results in the death of a person, it's caused by another person, it's with deliberate intent or reckless indifference, and it occurs outside the boundaries of the law. Effectively, all homicide investigations attempt to determine whether or not a killing fits these four characteristics. However, there are times when ending someone else's life is not only legal but encouraged. The most common is in cases of self-defense. US law states that you may use lethal force to defend yourself or others who are imminently threatened by deadly physical force. In most states, however, if you are able to avoid the situation or retreat, then you must do so rather than using lethal force. Exceptions exist in 23 states, known as "Stand Your Ground" laws. These maintain that if you are in a place that you are legally allowed to be, then you have no duty to retreat and can respond to deadly force with deadly force. Also, nearly all states have a form of castle doctrine. This gives greater leniency to assault against an intruder within your home, whether they pose a lethal threat or not. Outside of Texas, however, you cannot kill someone only to protect your property. Killing an enemy combatant as directed in a lawful war...