ThinkProgress points out the fallacies of a popular pro-gun theory, 'Good Guy With A Gun' Was On UCC Campus At Time of Massacre
The issue of whether UCC was a ‘gun free zone’ has become a source of controversy. Gun advocates argue that ‘gun free zones’ encourage gun violence by creating a space where people are unable to defend themselves.
This is not supported by the facts. According to a study of 62 mass shootings over 30 years conducted by Mother Jones, ‘not a single case includes evidence that the killer chose to target a place because it banned guns.’ Many of those mass shootings took place in areas were guns where permitted, but not a single one was stopped by armed civilians.
Parker’s interview revealed the practical difficulties of armed civilians trying to stop a mass shooting. By the time he became aware of the shooting, a SWAT team had already responded. He was concerned that police would view him as a ‘bad guy’ and target him, so he quickly retreated into the classroom."
They also write, The Sheriff Investigating The Oregon Shooting Believes Some Seriously Fringe Things About Guns. Seems he's an Oath Keeper and probably thinks Obama is trying to take everybody's guns.
Hanlin’s letter also blurs the line between a matter that is lawfully within state officials’ discretion and something much more akin to insurrection. Under the Supreme Court’s “anti-commandeering doctrine,” states may refuse to enforce federal laws that they do not wish to devote their resources to enforcing. For this reason, provided that state law gives him the discretion to do so, Hanlin is permitted to deny his department’s resources to federal officials seeking to enforce federal gun laws.
What Hanlin may not do, however, is unilaterally assign himself the power to decide what is or is not constitutional and then refuse to “permit the enforcement” of federal laws by “federal officers within the borders of Douglas County Oregon.” This rule stretches back at least as far as the late nineteenth century, when California charged a United States Marshal with murder after the marshal shot and killed a man who threatened the life of a sitting supreme court justice. In ordering the charges dropped, the Supreme Court explained that a federal official who “is held in custody in violation of the Constitution or a law of the United States, or for an act done or omitted in pursuance of a law of the United States. . . must be discharged.”
If Hanlin believes that the federal government is acting unconstitutionally, he can file a lawsuit challenging the federal government’s action. But local sheriffs are not permitted to use the powers of their office to thwart federal officials trying to carry out their own duties.
Vox of course had a nice all inclusive piece, America's gun problem, explained.