The public have to adapt to this. This means paying attention to your surroundings, the buddy system, and most of all carrying concealed weapons that can be quickly deployed and stop the commission of these felonies.
Young black people have to be looked at with suspicion relative to the situation. Young black males especially. Moving in your general direction at 50 feet you should be getting ready to brandish.
At 20 feet, a command voice command of halt is not inappropriate, and if disregarded, your weapon should be brandished “for use” not for just display. If he enters your space within 20 feet, you are borderline legal to shooting or stabbing him.
If you do, remember that it is your word against his, so if he is not saying, you will usually win in court.
An increasingly common homicide trend is the multiple perpetrator/lone victim style of attack. This means it will be your word against the word of the victim’s friend(s). If you take them all out, it will be your word against the word of the national media. It’s best to just cross the street and avoid confrontation. If they cross too and continue towards you, prepare yourself for combat.
After Zimmerman, forget the cops and court. If I have to fire, I'm getting out of dodge and then keeping my trap shut.
Your advice is generally spot on, but I have a slight problem with the distance involved here. Not long ago, taking a course in self-protection by firearm, we arranged for one of the younger, fit students to charge, from 20 feet, another one who had a fake gun in his holster. We timed it and found that the "assailant" got to the "victim" in one and a half seconds. The victim did not have enough time to draw and point his gun.
So, if one were to call out "Halt"! at the perp while simultaneously drawing his gun I think he would have a better chance of prevailing.