Reddit mentions of In the Line of Fire: Youth, Guns, and Violence in Urban America (Social Institutions and Social Change)

An impossible Utopia like Japan, Australia or Sweden you mean? The US is closer to Zimbabwe in gun deaths that those places so well done there, if that's what you're aiming for.

A "Level playing field" is provided by a judicial system and enforced by the police (additionally the good police forces don't have guns either - UK), and not by allowing every Tom, Dick and Dirty Harry the ready ability to murder dozens of people in an afternoon.

I have a civil right to defend myself in pretty much any first world country I can think of, I can do so by running away, punching somebody in the face, calling the police, picking up a chair and throwing it. Running away from a person with a knife or a club is so much easier than outrunning a bullet.

Your article repost was pointless really wasn't it, it has no data and is not a study, it's some dude called "TZO" taking a logical leap and saying he thinks guns prevent some violence because they act as a deterrent. That's just baseless opionion, come on you can do better so let help improve your source material; This thinking comes from places like the 1995 Sheley and Wright book and the famous "More Guns, less crime" from the Lott & Mustard report.

The latter paper concludes about 1,500 less deaths a year countrywide had gun ownership been more widespread. It goes on to state that crime costs in total would rise by over $5 billion, because guns are the most valuable asset that can be stolen after cash and lead to a higher rate of burglaries.

So now you've got some old theories I'll show you that they have been largely debunked in about a dozen newer papers such as "The Effects of Gun Prevalence on Burglary: Deterrence Vs Inducement" by Cook and Ludwig that concludes, "Other things equal, a gun-rich community provides more lucrative burglary opportunities than one where guns are more sparse. The new empirical results reported here provide no support for a net deterrent effect from widespread gun ownership. Rather, our analysis concludes that residential burglary rates tend to increase with community gun prevalence".

The "Deterrence effect" of which you speak is also largely discredited in the area of nuclear proliferation.