Thats bull, a gun's purpose is self defense. Defending yourself doesn't mean shoot for the heart when you're attacked, it's to maim and maintain. Killing with guns is only if you are a criminal, fighting in a war, but a gun isn't made to slaughter people.
In most places (including most places in the USA, I believe), guns are classed as deadly weapons. Because of this, use of them for self defence is considered to be justified only if killing the attacker is honestly believed to be the only way get out safely. If you shoot (or knife, for that matter) at someone then say "I was aiming to wound, not kill", you get in more trouble 'cause that means you didn't need to kill them, therefore deadly force was excessive.
I say this because I wouldn't want anyone here to get the wrong idea and end up in prison for trying to avoid injury/death. Of course, anyone who does own or intends to own a weapon with the purpose of self defence should consult a professional lawyer/legal knowy person, as I'm not one and laws vary widely depending on one's location

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They are excessively efficient at killing though. Joe Schmoe with a Neon Green Hat isn't likely to be able to kill two people up close with a knife, much less a police officer, with 1/10th the ease he has with a gun.
Actually, if you use the qualifier "up close", that statement is arguable at best. If you are within arms length of a person with a knife, you are in deep [censored] if it's drawn, and at high risk if it's not (pretty much anyone can pull out a knife and slash you nastily within a second or two, with little warning). If someone has
any weapon at all, your priority should be getting the hell away from them.
Fighting is bad, as that's completely the wrong mindset for survival/self defence. Think, "How can I get out of this situation?" not, "How can I take this guy down?"
This public service announcement brought to you buy mangos and bananas, tasty tropical goodness in a skin.EDIT: Oh, yeah, and this particular shooting is sounding like it's crime related, rather than having anything much to do with the VTech.