I have never heard of or witnessed a buyback event where a bad guy turned in a weapon nor have I heard of any weapon that was turned in that was found to have been used in a crime. What I did observe were many senior citizens, mostly women, turning in their now deceased husbands weapons. I turned in many fine collector grade weapons at last years Tampa buy back. Lets see, I turned in a Jennings/Bryco, Rohm and a Lorcin. Note: none of these weapons were in safe operating condition from new out of the box.
US Army 1953-1977
We, the People are the rightful masters of both Congress and the courts not to overthrow the Constitution, but to overthrow men who pervert the Constitution.