Is the intentional unlawful killing of a human being by another person that is not premeditated or planned in advance and that is committed under circumstances that would cause a person to become emotionally upset?

This is an example of voluntary manslaughter. 
Some American states call this crime a third-degree murder, although generally it is known as voluntary manslaughter. It happens when a person didn't plan on murdering anyone, but happened so in a fit of anger, for example. An example of such a crime would be if a husband came home and saw his wife cheating on him with another man, and he kills one or both of them in the heat of passion.