OKLAHOMA CITY (KFOR) – A national database run by the FBI allows gun sellers to process background checks within minutes to ensure a buyer is eligible.

The National Instant Criminal Background Check System, known as NICS, uses criminal records from local and state jurisdictions to determine whether someone’s gun purchase can proceed, be delayed, or even denied.

Gun stores have customers fill out paperwork or forms on the computer. The information is then uploaded into NICS and results come back before ever needing to leave.

“We call them directly, and we can typically have an answer on a proceed or a delay or denial within 10 minutes,” said Mike Rust, General Manager of H&H Shooting Sports in Oklahoma City.

If the results don’t populate records of violence or other activity deemed a threat to others, then a customer can proceed to buy a gun.

When information shows records as questionable, the process can be delayed. An examiner would look at the documents to determine if it can proceed or be denied, which takes about 3 days.

But some customers can be flatly denied. A denial would stay with that person in NICS, so no matter where they go to buy a gun, the system will flag them.

On Wednesday, June 1, a gunman entered the second floor of the Natalie Building at St. Francis Hospital in Tulsa. Four people, besides the gunman, were shot and killed. He bought the AR-15 used in the attack only hours earlier.

Many critics questioned how the laws allowed for such a quick purchase with minimal checks.

NICS collects a vast amount of data. Rust said the more information it has, the better the system works.

“It’s an extremely large building full of servers which all contain documents about every person in the U.S. If you get a ticket, there’s a document in that database about you,” said Rust.

Gun purchasing background checks are different than other background checks.

Instead of analyzing criminal information, many background checks look at employment records, credit history, and other information that may take more time to acquire.

There are even differences within gun-buying state-by-state.

Rust said California does not have NICS approve their background checks. Information from NICS is used, but the approval process is run through the state. Even without their mandatory wait periods, that process can prolong the approval time.

“They’re not going to process a background check if they don’t have time to do it,” said Rust, acknowledging how more bureaucracy can slow down purchases.

As the nation reels from nearly weekly mass shootings, people are learning more about gun regulations and laws close to home.

Oklahoma PTA, the state’s largest and oldest child advocacy group, passed a resolution late last week calling for universal background checks for all gun sellers, including private sales, and proposed enhanced red flag laws.

Rust said there have been movements in the past to add more data to NICS to include mental health information.

The movement is called FixNICS. It advocates addition information like mental health adjudications and involuntary commitment orders, which they claim can stop the wrong people from buying guns.