Correlation does not equal causeation.
Yep there was a drop in those regions that were generally more gun friendly. So that makes them seem better off, right?
Not so fast. The NE which showed the least reduction already was at a level much lower than the more gun friendly regions.
2009 showed similar reductions, but look at the base from which the reductions occurred.
http://www2.fbi.gov/ucr/cius2009/data/table_03.html
So the south had the greatest reduction? In 2009, they also had nearly triple the violent crime rate as the NE. So if you want to claim that violent crime went down more because the South was more gun-friendly than the NE, then how do you account for the South being so much worse off in the first place? Is the overall higher violent crime rate of the South also correlated with being gun friendly?
Did you ever think to consider that the reason why such places showed the most improvement were because they were places that were so much worse off originally?
A lot of the cities in the gun friendly South are also the cities noted as being some of the most unsafe in the country in regard to such crimes. Some of the safest cities were in the gun unfriendly NE as well.
http://www.bestplaces.net/docs/studies/crime1.aspx