The 5 states with the highest per capita gun homicide rates are DC, LA, MO, MD and SC (in decreasing order). The states rated highest by the Brady Campaign (Ostensibly the most gun un-friendly) are CA, NJ, MA, NY and CT.
Gun violence in the United States by state - Wikipedia, the free encyclopedia
Now, Brady doesn't count DC. I don't know exactly what their reasoning is but DC is about the most gun unfriendly place in the states and it has a gun homicide rate more than DOUBLE that of the next highest state. If I were the Brady campaign I wouldn't list it either. But that's neither here nor there in these discussions. Let's look at the other states we're talking about:
Louisiana is a pretty gun friendly state. In 2012 Baton Rouge had 66 homicides and New Orleans had 193. The rest of the state had 236. The cities of Baton Rouge and New Orleans account for 600k of Louisiana's 4.6M residents or 13% of the total population but more than 50% of the homicides. In other words you're 4x more likely to be a homicide victim in either of the major metropolitan areas than you are elsewhere in the state. That would indicate that it isn't gun laws that are a problem in LA, it's urban blight.
Missouri is slightly less gun friendly than Louisiana. In 2012 there were 389 murders in MO. 113 of those murders were in St Louis and 105 were in Kansas City leaving 171 for the rest of the state. Those two cities account for 782k of Missouri's 6M population or 13% of the total population with more than 50% of the homicides. Again, this isn't a problem with gun laws, it's an urban blight thing.
Missouri crime rates and statistics - NeighborhoodScout
Maryland is ranked 7th as the most gun unfriendly state and is one of only 11 states receiving 2 or more stars from the Brady Campaign. This state had 372 homicides in 2012. 218 of the homicides occurred in Baltimore. Baltimore has a population of 625k or roughly 11% of the nearly 6M total population of the state. They also have more than 50% of all the homicides. Once more, were looking at gun laws being less of an issue and urban blight being more of an issue.
Maryland crime rates and statistics - NeighborhoodScout
South Carolina is the last state in the top 5 for our purposes. There were 322 murders in SC for 2011 and Brady has them in a tie for 22nd most gun un-friendly. South Carolina doesn't really have much in the way of major urban areas but their homicides spike in 4 particular counties (Charleston, Greenville, Horry and Richland). Those counties account for 32% of the state population and 34% of the homicides. One interesting thing about South Carolina is that firearms seem to be used in only 67% of homicides as opposed to 80% or so in the other states we were looking at.
Based on this small sample I think you'll get the idea that gun laws ARE NOT a good indicator of how likely a homicide is to take place and that high population densities are a MUCH better indicator.