One of the things is, the criminals tend to have even
worse training than your average Joe Citizen or cop. As heavily the deck is stacked against a law-abiding citizen if they've got a gun and the criminal has a knife, it's even worse if it's vice versa.
Seriously, hand-to-hand training trumps pretty much everything, at that range. At longer range, it's harder than it looks. Most criminals are phenomenally bad shots, though there's always the rare exception. In any case, though, shooting someone is hardly easy, both in terms of technical skill and emotional impact.
And criminals
will indeed still have guns. Maybe not as many,
but, you generally end up stacking the odds against the law-abiding people. Remember the Germany statistic? It's more like 10:1 the other way around in the USA. In Jamaica, possession of a handgun is punishable by life in jail. They still use handguns. But those comparisons are meaningless. Different cultures.
"Needing" guns, or any other weapon, is a
symptom of a
social problem. No amount of bans will
ever make crime go away, or really even have a significant effect on crime, given that close combat weapons have worked for millenia, fists and feet for even longer than that.
Actually, against cops in PA, anyway, you're better off with a frying pan or unarmed, statistically.
http://ucr.psp.state.pa.us/UCR/Reporting/Annual/pdf2008/a184r001.pdfCouldn't find national data, but PA tends to be really close to average.
What you should really do is look at England's crime rates, from multiple sources, and put in dates where gun control laws were passed, as well as dates where social things were passed, like better health care and education in poor urban areas. See whether social stuff correlates to a slow drop in crime over a period of 13-16 years, followed by a relatively sudden sharp drop (assuming English gangsters join gangs young, too). Gun control,
if it works, should produce a
permanent increase in the rate of crime reduction, and reasonably quickly. And if it
actually works, it should reduce
all violent crime. Reduction of "gun crime" is meaningless, if criminals switch to butcher knives and cricket bats.
Nothing like that's ever happened in the USA. Just correlation to social stuff.