The criminal justice system is not just, but it certainly is criminal the joke goes. Its as flawed as everything else we humans have constructed but it is better than the chaos and anarchy that would rule without it. What if the story had read, granny mistakenly shoots wrong guys because of mis-iding them. The old saw goes we would rather have 100 guilty go free rather than convict one innocent person, it all seems very academic until you are in the defendent's chair and you didn't do it.
I am not a promoter of gun control, I agree with Hillbilly, if law abiding citizens, especially women were armed then justice could be possibly dispensed at the time of the act, not after the fact. In my state attempted rape is lawful cause for a woman to use deadly force to protect herself, that's when the shooting should take place if it is going to take place.