What are the highest gun restrictions ? How many of these violent crimes were actually done with firearms, how many of those firearms were obtained legally ? Those are the real questions.
In Chicago and NY, the 2 cities in the US with the highest crime rates in the US, it is essentially impossible to obtain legal firearms, unless you are a politician, and had a ban on most types of them (heck, the court had to strike down as unconstitutional like 12 laws recently in Chicago). On the other hand, states with very liberal gun laws, like Texas and New Mexico, have the lowest violent crime rates in the US. These are simple facts Kafein...you can't really dispute them.
Also, Switzerland isn't one of the countries with the lowest crime rates because the gun laws are laxist, duh. You know, I could show you graphs of the average temperature during the south african summer the same years as new rambo movie releases and make a correlation between the temperature and the size of rambo's shirt on the dvd case. Any reasonable human being would see a pattern here.
What you say might or might not be true, however it definitevely doesn't help the correlation that guns "produce" crime. You might argue that less pirates cause global warming, but the definitevely can't argue that less pirates cause global cooling since there are now both less pirates and more heat....
....I am not sure if you get my analogy, but hey, pastafarian references.