I've read all the letters and the pro-gun control and anti-gun control people are talking past each other. There are two issues here: philosophy and causation. The philosophy issue trumps the causation issue, but both argue in favor of less gun control.
The philosophy of the US government is that any authority it has is derived from the people and strictly limited by the Constitution. The government does not give guns to the people; the people give guns to the government. The US founders were paranoid about tyrannies (justly so!). The second amendment is there to allow the people to overthrow any attempted tyrannical coup. This is explicitly authorized by the Declaration of Independence. I know this is alien to everyone outside the US. But this is the way it is.
The issue of causation is: does crime go down with more gun control or with less gun control? I am very dubious of country to country comparisons because of the differences in demographics and cultures. Rather, I like to compare changes with a country and within the US states. States are free to vary their gun control laws as they wish. States with less gun control have lower crime rates than those with more. The locations with the most draconian gun control are Washington DC and New York City, which also have some of the highest gun crime rates. Notice Washington DC's gun control laws didn't help prevent the latest terrorist sniper.
Outside the US, the recent gun control laws introduced in the UK and in Australia have led to higher crime rates. For those who wish to introduce gun control, you must first show that it reduces crime.
I close with a question for the readers here: Do you feel safer with private citizens owning guns or with the government? And why?
Problem is that it is hard to know if this is a matter of causation or association.