Gun stores across the metro area tell 9NEWS sales are up, classes are full, and customers are asking questions.
Brandon Baker, owner of Rocky Mountain Guns & Ammo in Parker, says the phones won't stop ringing, and the customers won't stop coming.
"Past few days have been absolutely crazy," Baker said.
Baker says the theater shooting triggered a dramatic spike in sales.
"It really hits home," Baker said. "I need to be able to protect myself and my family."
The Colorado Bureau of Investigation approved background checks for 2,887 gun customers between Friday and Sunday. That is a 43 percent increase over those same days last week.
CBI spokesperson Susan Medina took 9NEWS inside the office where those background checks are happening.
"We search seven databases to make sure that individuals have the right to purchase and posses that firearm," Medina said.
The FBI reports similar spikes after other major shootings, like Congresswoman Gabrielle Giffords in 2010 and Virginia Tech in 2007.
For gun shop owners like Baker, it means a big boost in business during the normally slow summer season.
"Anytime something happens in government or worldwide or within our own country, people want to be able to protect themselves," Baker said.
Baker says it is not uncommon for gun sales and training to increase during a big election year.
Just days after the theater shooting comes the inevitable debate over guns and ammunition, with some lawmakers calling for restrictions.
US Representative Diana DeGette (D-Colorado) is joining lawmakers from New York and New Jersey as they call on congress to ban the type of high-capacity ammunition clips used by theater shooting suspect James Holmes.
They want to do away with the 100-round magazines that allowed 70 people to be shot in a matter of minutes.
Baker says it's not guns or ammunition that kills people, but the person who pulls the trigger.
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