Credit: AP

Background checks for gun sales and permits to carry guns--indicators of how healthy the gun business is--have been soaring since the mass shooting at a Connecticut elementary school, according to the FBI.

It's not the first time a mass shooting has sparked this kind of surge; firearm sales also increased in the days following the Aurora, Colo. theater shooting.

But in Colorado and Connecticut, citizens have been far less enthusiastic about gun purchases. Background checks in both states increased during the months of November and December, but at a much smaller rate than other states.

Between Aurora and Newtown, citizens in those states not only suffered the deadliest mass shootings of 2012, but two of the worst mass shootings in U.S history.

The FBI says buyers across the country have been particularly energized since the Newtown massacre, likely due to the trifecta of the particularly horrific nature of the shooting spree in which a gunman slaughtered 20 first-graders, President Barack Obama's re-election, and Obama's promise post-Newtown to support new gun control legislation.

Outside of Colorado, the biggest surges in gun ownership have been in the West and South. Nationally, there were twice as many background checks for firearms in November and December than there were during that same time frame one year earlier.