CSGV..Gun laws don't work

The Coalition to stop gun ownership violence is at it again, but got called on their lies. In their tweet messages, the contend that the private sale 'loophole' was responsible for the Columbine school shooting. They claim that the shooting was preventable if only we had just one more law, a law that would require everyone to have a background check prior to purchasing a firearm. Indeed, a law that would require that every purchaser pass a NICS check, would reduce the number of criminals or otherwise prohibited persons from legally purchasing a firearm. The problem, criminals simply don't obey the law, whether selling firearms or buying firearms or using firearms to commit crimes. CSGV agrees.

Now, why a background check on the private sale of firearms would not have had a effect on the Columbine shooting. Both of the shooters were 17 years old at the time. They were already prohibited from purchasing a firearm. The two men that sold firearms to the 17 year olds, knew that they were under age, but sold them a firearm anyway, so even if there was a requirement for a background check, clearly the sellers and buyers in this case would not have followed the law. In addition, the shooters built 99 improvised explosive devices, which is already against the law, a law that they did not adhere to.

What's your thoughts?