https://www.npr.org/sections/thetwo-way/2013/05/07/181998015/rate-of-u-s-gun-violence-has-fallen-since-1993-study-says

"In 2004 (the most recent year of data available), among state prison inmates who possessed a gun at the time of the offense, fewer than two percent bought their firearm at a flea market or gun show," according to the Bureau of Justice Statistics. "About 10 percent of state prison inmates said they purchased it from a retail store or pawnshop, 37 percent obtained it from family or friends, and another 40 percent obtained it from an illegal source.."

Wait... what about that gun show loophole? Gun violence is down?