A cop buddy of mine summed up his patrol work in the hood with, "I am just a babysitter for grownups who don't know how to be grownups."
That is the thing to remember when considering self and home defense options. There are just too many criminals out there like this. It really pains me to read self defense stories or some arrest story where some criminal is caught and they find out his record is a mile long. It always seemed to me that either they are gaming the system or the justice system is not dealing with the career criminal properly.