The shooter who killed 17 kids, teachers and coaches at a school in Florida used an AR-15 assault rifle.
To fix the problem of mass shootings requires an understanding of how the system works. ABC15 visited an East Valley gun store to learn the process of buying an AR-15.
AJI Sporting Goods owner Jeff Serdy said, in Arizona, a person must be 21 years old and an Arizona resident to buy a handgun. The age to buy a long gun is 18. Even though an AR-15 is called an assault rifle, it's simply a long gun for legal purposes, so the age required to buy one is 18.
A person who wants to buy an AR-15 must present a valid government ID and pass an FBI background check. The background check has three possible answers: approved, denied or delayed. Serdy said a delayed background check generally means there's a clarification of common name or other information that requires further investigation, which generally takes three business days.
If a gun buyer has a clean background they are approved instantaneously. The entire process of filling out, submitting the form to the FBI and receiving approval happens at the front counter in about 10 minutes.
"It's the same system as when a police officer carries your ID back to his car and punches it in," said Serdy.
Denial is also instantaneous and generally has to do with crimes committed or violence in the prospective gun buyer's past. Lying on any of the background check questions is a felony.
"Have you been convicted in a court for a misdemeanor?" said Serdy, reading from the form. "A lot of people think it's only a felony. If it's domestic violence, even a misdemeanor will stop you from purchase."
Background check aside, Serdy said he won't sell to someone who gives him an uneasy feeling. He said just last week two people came into the store with sunglasses and hoodies covering their faces. They didn't try to buy guns but he would have refused the sale if they had.
"People's lives mean more than making the few dollars we make on selling a gun," said Serdy.
But with all these barriers we're still left wondering how to keep mass shooters away from our kids. While many on the left believe that stricter gun control and enhanced background checks are the answer, gun experts have their own ideas.
"I think more resource officers [in schools]," said Serdy. "We protect our banks, we protect our Circle Ks with armed guards. I think there should be an armed guard somewhere in every school."
RELATED: What Arizona schools are doing to keep kids safe
Arizona gun law expert Alan Korwin thinks we need to stop giving infamy to mass murderers.
"Refrain from repetitive use of mass murders' names and images. But I could turn on the TV right now and you will hear this heinous criminal's name constantly. Bad idea," said Korwin.