...permissible to use lethal force only when your life is directly threatened.
Furthermore, when the immediate threat is gone - a shot intruder, say, goes down with a bullet in the leg - the self-defence argument ends.
"The law says that you have to stop the moment that you have repelled an attack, so
normally one shot will suffice," said Steven Tuson, a professor of criminal law at Johannesburg's Wits University.
If Pistorius's lawyers choose to avoid the self-defence avenue, another option may be to argue temporary insanity based on chemical stimulants, a defence irreverently referred to in sports-mad South Africa as "roid rage", short for 'steroid'.
This is why Pistorius was taken for blood tests immediately after the shooting, Tuson said, "to exclude that defence". Classen also said the "roid rage" defence could only succeed in "extraordinary circumstances".
One other possible avenue is for Pistorius to argue "putative self-defence" - that he thought he was being attacked even if he wasn't. Even then, Classen said the content of the media reports, if true, curtailed his chances of success.