When Can You Lawfully Use BJJ As Deadly Defensive Force?

Most people think of Brazilian Jui-Jitsu (BJJ) as a non-deadly means of self-defense, and imagine using such skills to defend against a non-deadly force attack. There are, however, many techniques in BJJ that readily qualify as deadly force--because the definition of "deadly force" include not only force that can kill but also force that causes serious bodily injury. The many joint locks in BJJ that can utterly destroy a joint certainly would qualify as deadly force if carried to com...