mozambique drill

The Mozambique Drill (also known informally as "two to the body, one to the head") is a close-quarters combat shooting technique. The shooter fires twice into the torso of a target (known as a double tap) and then, if the target is still active, follows up with a more difficult shot to the head: if properly placed, the headshot should kill or otherwise stop the target if the previous shots failed to do so.

It's s common misconception, but the final head shot is not a requirement: the final shot is only fired if the previous two shots fail to incapacitate the target.