A recent case about this is about the student Gaston Mansilla Yupanqui. He was being mugged by two attackers with switchblades and defended himself with a .38 caliber pistol. One of the attackers died after being shot. Mansilla ended up arrested and in the same jail as his other attacker.
Should he have let the muggers get away with it? Fortunately after a huge controversy, he was released.