A spike in gun sales is common after a mass shooting, but the latest rampage has generated record sales in some states, particularly of rifles similar to the AR-15 the gunman used in an attack Friday on Sandy Hook Elementary School that killed 26 people, including 20 children.
Colorado set a single-day record for gun background check requests the day after the shootings, while Nevada saw more checks in the two days that followed than any other weekend this year. Records were also set in Tennessee, California and Virginia, among others.
Some gun shop owners stopped selling their remaining stock of military-style rifles, anticipating only more interest and value after President Barack Obama on Wednesday instructed his administration to create concrete proposals to reduce gun violence.
Robert Akers, a Rapid City, S.D., gun seller who specializes in such rifles, said the rush of customers had transformed his Rapid Fire Firearms store into a "madhouse" and that he's not actively selling the guns and has turned off his phone.
"The price is only going to go up higher," he said.
There was also an unusual increase in sales for armored backpacks designed to shield children caught in shootings, according to three companies that make them.
The armor inserts fit into the back panel of a child's backpack, and sell for up to $400, depending on the retailer. The armor is designed to stop bullets from handguns, not assault weapons like the one used in the shooting at the Newtown, Conn., school.
Still, the manufacturers and some parents say that while they don't guarantee children won't be killed, they could still be used as shields.
Ken Larson, 41, of Denver, Colo., already had an armored backpack for himself and persuaded his wife to buy one for their 1-year-old after the latest shootings. He knows the backpack won't guarantee his son's safety. But, he added, it was a worthy precaution.
"It's a no brainer. My son's life is invaluable," Larson said. "If I can get him a backpack for $200 that makes him safer, I don't even have to think about that."
Some experts, however, say sending children to school in armored backpacks is not a healthy response to fear about mass shootings. Anne Marie Albano, psychiatry director at Columbia University's Clinic for Anxiety and Related Disorders, said parents should convey calmness, not anxiety.
"This is not serving to keep children safe," she said. "This is serving to increase their fear and their suspicion of their peers."
At Amendment II in Salt Lake City, sales of its children's backpacks and armored inserts have increased, with 200 purchase requests Wednesday alone.
"The incident last week highlights the need to protect our children," said co-owner Derek Williams. "We didn't get in this business to do this. But the fact is that our armor can help children just as it can help soldiers."
Kerry Clark, president of Texas-based Backpackshield.com, began making the backpacks after the deadly mass shooting at Virginia Tech in 2007. Clark said he sold 15 backpacks Wednesday. Prior to Friday's shooting, he said, the company would sometimes go an entire month and just sell one.
"It's the busiest I've seen it in my life," he said.
Bullet Blocker, a Massachusetts-based company that sells the backpack armor, declined to provide sales numbers but noted that recent sales were substantially more than normal.
Sales of assault weapons also were on the rise.
Austin Cook, general manager of Hoover Tactical Firearms in suburban Birmingham, Ala., said the spike in sales since Friday's shootings has been so intense that federal background checks that typically take five minutes or less are now taking up to an hour.
Cook said about 50 people were waiting in line for his store to open the morning after the shootings, and that he's since sold nearly all of his assault weapons. Now, he's trying to find more distributors.
"I can't keep them in the store," Cook said.
In Pittsburgh, Dick's Sporting Goods said it was suspending sales of modern rifles nationwide because of the shooting. The company also said it's removing all guns from display at its store closest to Newtown.
Aaron Byrd, co-owner of Patriot Shooting Sports in Youngsville, N.C., is sold out of the AR-15 rifles, ammo for those types of guns and high-capacity magazines.
"Things have been crazy the past couple of days. A lot of people have been coming in looking to purchase semiautomatic rifles. They're worried that the government's going to ban semiautomatic rifles and high-capacity magazines, so they've been coming in looking for those," he said.
He added, "I think it is a knee-jerk reaction by both parties — both the government and the citizens."