Zero Hedge has an article examining gun statistics for the United States. For some reason, the author assumes gun ownership as bad. Thus, that the number of households owning guns has fallen over recent decades is "good", that the number of guns per capita has increased is "bad". I don't agree with that sentiment, and the facts of lower crimes certainly beg the question of whether that distinction is correct. In any event, the author also notes that the majority of violent crimes are committed by a very small number of repeat offenders. Also, I would take note that comparing U.S. homicide rates to those of other countries is not as straightforward as it seems, since when and how a death is included as a homicide varies.
Finally, compare these two graphs:
What immediately strikes me is that, overall, nations with higher rates of gun ownership have lower homicide rates.