Well, given that state breakdown, I think the right conclusion is that there are simply more murders in the US than other developed countries across the board, no matter how you slice it.
Well, I somewhat disagree about that. State-level slicing is a reasonable approach because then the units of comparison are typically more similar in size. And there are several U.S. states (New Hampshíre, Hawaii, Vermont, Maine) that have a lower homicide rate than Belgium, Lichtenstein, Taiwan or Estonia.
(Yes, comparing rather marginal differences.)
However, Venezuela is on a completely different level. Moreover, murder rates in the US are heading downwards; they are half of 1980's numbers. Venezuela is radically up, almost ten times of 1980's numbers.
Imagine you broke down Belgium, etc the same way the US is broken down by state. You'd get even lower murder rates in many areas of Belgium, that would make the safest areas of the US look dangerous by comparison.
If you break down Belgium to parts that are similar in size to U.S. states, you end up with one Belgium.
(However, breaking up Belgium brings to mind some controversies: the motto of the country is "Einigkeit macht stark" or "Unity makes Strength"; after the 2010 election (June 13, 2010) it took 541 days of negotiations to come up with a functional government (sworn in on December 6, 2011).
http://www.deathpenaltyinfo.org/murder-rates-nationally-and-...
Every single state is above the UK's murder rate of 0.9.