In either scenario, you commit a crime. In the end, you kill someone! When someone is "murdered," the act of killing them is intentional or purposeful. Typically, it is planned and executed in a heartless manner. Because of this, the penalty for murder is extremely harsh. "Manslaughter" involves a killing that may or may not have been planned. You might unintentionally end up killing someone.
Murder occurs when someone kills their aunt or uncle in order to take their property. Manslaughter occurs when a pedestrian is driven over.

Killing someone out of self-defense is manslaughter, not murder.
 
The murders in Noida have upset many people in our country.