OK, I could be wrong but...gun laws...

Whenever a Facebook meme makes a claim like this, my red flags go off.  Here is the claim.

• 25 States allow someone to carry a gun down the street with no permit of any kind
• 4/5 murders are committed in the other half of the country.

OK, I assume that Andrew is talking about "open carry" states where you can carry your weapon as long as it is not concealed.  My source for these states is OpenCarry.org. [1]  I know this type of source is very unlike me, but I used them to verify the maps I altered from another questionable source Wikipedia. [2]   My source for homicides is much better.  Though four years old, I used the Deaths: Final Data for 2009, made available by the CDC. [3]  Even though, it is older, it should provide a base in which to verify Andrew's quote.  After all, he is alleging that less gun laws cut down on murder.  

Right off the bat, we run into problems.  There are twelve "open carry" states, not 25.  Added together, they had 2018 murders in 2009 and represented 12.01% of the total murders.   Andrew may have begun talking about crime rates in his next sentence and he should have.  A state with high population and a low rate could put out as many murders as a state with low population, but a high rate.  In 2009, the national homicide rate was 5.5 out of 100,000.  Four "open carry" states (Arizona, Nevada, New Mexico, North Carolina) were above the national average that year.  So 75% of "open carry" states were below the national average, but that is only eight states.  

There are fifteen licensed carry states where you can apply for a license to "open carry".  These states combined counted for 3081 murders in 2009.  They represented 18.34% of all murders.  With stricter gun laws, only three of these states (Georgia, Mississippi, Tennessee)  had a homicide rate higher than the national average.  So 80% of the licensed carry states were below the national average.

In case you were wondering 20 states were at or above the national average.  As mentioned already, only four of them were "open carry" and only three were licensed carry.  I don't know if this has necessarily anything to do with open display of fire arms.  Alabama's homicide rate is lower than Georgia's and much lower than Mississippi's.  With the exception of Kentucky and Virginia, the South was equal to or higher than the national average.

Anyways, let's just evaluate the claim.  There are not 25 states with "open carry".  Even if you add licensed carry, you run over to 27 states.  Yes, almost 9/10 murders occur in not open carry states, but that was not the claim.  The claim was that half the states, with stricter gun laws, account for 80% of the murders.  Licensed carry and "open carry" combined amount to about 30.35% of all the murders.  This leaves about 69.65% account for by the stricture states.  While this may be more than 2/3, look at the states in question.  Many of them have lower populations and produce less murders.  Even with a higher homicide rate of 8.7, New Mexico put out less than half of the homicides of Arizona with their  5.9 rate.   Yet the main point is that it is not the 4/5 claimed.