Does any agency keep statistics on the number of people from countries with defenseless, unarmed civilians who are murdered by their own governments? If memory serves, I believe there was a significant number of defenseless citizens murdered by, or with the complicity of, their governments during the 1930s and 1940s. That is a trend that continues to this day...in certain areas of Europe, Asia, Africa, and South America.
By the way, that 16,000 murders a year is a total of ALL homicides in the U.S., both justified and unjustified. Since many of these are drug or gang related, I don't think any changes are going to significantly effect the numbers, because those perps don't give a dam- about the law.