Gun and knife carrying for protection from criminals

Debate on knife and gun carrying on this blog lately has been significant. I've received another comment on the recent posts. Because it touches on key issues that others have flagged, I thought I would reproduce it here as a main post for all to comment on. Personally, I continue to disagree with the arguments presented. Fundamentally, people carrying weapons (guns or knives) is the wrong path. But, please review this post and add your opinion (it was sent to me by a Tom Trumper, presumably a 'pen name'):

" Sir, While I believe that Lucy Cope has had a terrible loss - probably one that I will never be able to comprehend as I am not yet a father - I do not believe that this makes her immune to criticism. If anything, her involvement undermines your efforts to outlaw firearms as she is clearly driven by emotion, and showed this very strongly during the television show. And you'll forgive me if I question Lucy's stance on the story of the elderly woman being raped - that the preferable alternative for the elderly woman owning a firearm was for her to own a panic alarm. While I can see the argument here, I believe that it is alarming where an abuser of our most vulnerable citizens is potentially allowed to go scott free when the police cannot intervene in time. The point is here, an elderly woman is incapable of defending herself effectively most of the time, and a gun makes for a crude equalizer. When I say equalizer, I mean that physical strength or height plays little or no role in the functioning of a firearm compared to a knife, where a stronger, taller opponent can easily over power a rival. Because of this, citizens most at risk of attack (the weak, the old, the crippled etc) have a means of defending themselves - the same goes for items like 'pepper spray' and 'tazers'.

The firearm in question doesn't even need to the criminal to prevent the crime from happening, as a survey of imprisoned criminals in the U.S showed that 34% of criminals had either been "scared off, shot at, wounded or captured by an armed victim."(1) This shows that firearms can be a crime PREVENTER as well as a potential crime cause.

I am a firm believer in that certain prevention is better than uncertain cure, which could be described as a criminal being having to think twice before he decides to attack that young/old lady, as opposed to the same lady being maimed/killed/raped and the criminal having to be punished - we will never know if the criminal incarcerated in jail will be rehabilitated, but we will always know that it's a positive thing if a person can walk down a street without fear of being attacked.

I hope my comments are taken constructively and helpful in debate.

(source for my statistic about prevention: http://www.justfacts.com/guncontrol.asp )"