Re: 83 year old aikido black belt repels home invader.
I just don't think knives are very good home defense tools. There is a brandishing factor, of course, but if that fails and you have to use the thing, its a hell of a mess. Carpets will need to be replaced. I expect there will be a lingering smell of blood for years. The knife handle will be slick with blood and it will be hard to hold onto the thing; the weapon could be turned against you.