The number that the tout on background checks is something like 1.2 million denied checks. The # is misleading. The best analogy is the No List stopping Kenedy from getting on the plane 5 times. They count that as 5 instances where a terrorist was denied from flying but in fact the Late (and POS) Senator still manged to get on a plane at some point after he was initially denied. That was the analogy that I heard Lott use during an interview on Levin.
Very few denails stand with the NICS. People may be initially denied b/c the had a restraining order that was dropped or their name was similar to another person who is a felon. And the worst part, there is no system for following up with a criminal investigation for real felons that attempt to purchase a firearm.
Is it true that Lanza attempted to buy a new gun but was denied?