PHOENIX, AZ. (CNN/KNXV) -- It's normal to see back-to-school advertisements for things like backpacks and lunchboxes as the beginning of the school year approaches.
The owner of an Arizona gun shop says their back-to-school ad was all a big misunderstanding.
At Tombstone Tactical, the company has a very large online presence, according to owner Brian Smith.
On Saturday morning, he hit send to push out his weekly newsletter to his subscribers.
"The title of the program is called Shoot Now, Pay Later," he said.
He wrote: "now that the kids are back in school it's a perfect time to take advantage of some great specials."
"How that could be missed it's shocking, it's shocking," said New Mexico customer Marty Ryan who read the newsletter.
"I cannot believe these guys put this together as a promotion," said Ryan. "Especially when they use the words.. 'now that the kids are back in school let's have an assault rifle sale'."
Ryan is a gun owner, but his daughter is an elementary school teacher and his grand kids went back to school recently.
"It's always in the back of our heads. It's something that scares all of us," said Ryan.
Smith said "there's no way we would ever encourage violence at all."
"We just spent a bunch of money on our kids. Now it's time to spend a little bit of money on ourselves," he added.
He's convinced most customers didn't misinterpret the newsletter.
"I would apologize to anyone who took offense to that. We sent that email out to well over 200,000 people and I only received three negative responses," he added.
With multiple mass shootings less than 10 days old, the gun industry is once again facing scrutiny.
Tombstone Tactical says they go out of their way to promote gun safety and will now do a safety check on future emails.
"We will probably look at our emails a little bit better before we send them out," said Smith.
Most customers say they think the email was an honest mistake. And that they will continue buying from Tombstone.
As for Ryan, he says he's a former customer now.