Information in the post in part, comes from the 'Firing Line'
There are between 270-300 million guns in the USA. To put this in perspective, 4% of the worlds population owns 50% of all privately owned guns in the world. Some would think this would mean that the USA should have a homicide rate over 12x (50% divided by 4%) higher than the rest of the world.
In 2012 the United Nations Office on Drugs and Crime compared intentional homicide rates for most countries in the world. USA's rate was 4.8 per 100,000 inhabitants while the worldwide average was 6.9. These figures mean you are 30% less likely to be murdered in the USA than elsewhere in the world.. The 4.8 homicide rate is not even close to 12 times higher than the rest of the world.
So much for the hypothesis that more privately owned guns cause more murders.
Now, before you start throwing out how Japan, Australia, UK, Canada where guns are banned have rankings more favorable than the USA in homicide rates, so do Switzerland and Finland which have high rates of private ownership. In fact, Switzerland's homicide rate ranks 42% lower than the UK's. And of course, the gun control movement never mentions Mexico, Brazil and South Africa where private ownership is very difficult and which have homicide rates far above those of the USA.
While the hypothesis that high gun ownership rates cause a decrease in homicide is still being debated, the inverse that high gun ownership causes high homicide rates- is most certainly dead in the water.
-Geaux