The operative principle at law is called “disparity of force.” It means that while your opponent(s) may not be armed with a deadly weapon per se, their physical advantage over you is so great that if their ostensibly unarmed assault continues, you are likely to die or suffer grave bodily harm. That disparity of force may take the form of a much larger and stronger assailant, a male attacking a female, force of numbers, able-bodied attacking the handicapped, skilled fighter attacking the unskilled, or – in this case – position of disadvantage.Trayvon Martin was NOT "unarmed".
As older individuals, neither my wife nor I can tolerate what these savages blithely pass off as an ‘ass-whoopin’. Such an event can be life threatening.
Therefore, I offer a simple rule to all those Thugvon wanna-bes: Assault either me or my wife and I will kill you. Without mercy. Without a speck of remorse.