Every year there are more firearms found at airports — should you be concerned? 

The Transportation Security Administration (TSA) has reported that 6,737 firearms were stopped at the nation’s federalized airport security checkpoints in 2023. This is an increase of just under 3 percent from 2022, when 6,542 firearms were detected. On the surface this may raise an alarm for travelers; however, a deeper dive into the numbers suggests otherwise.  

In 2023, over 858 million people were screened at airport security checkpoints, up from 760 million in 2022 — an increase of nearly 13 percent. Therefore, if firearms are distributed uniformly across all passengers, the TSA caught fewer guns per capita in 2023 than in 2022 (7.8 firearms per 1 million passengers versus 8.6 firearms per 1 million passengers). Indeed, if they caught firearms at the same rate, they would have found 7,389 firearms in 2023.  

Does that mean that around 650 firearms were missed?  

Perhaps. But not all passengers carry a firearm with them to an airport security checkpoint. Moreover, firearms are not being found uniformly across all airports.  

In states with more lenient gun laws, like Texas and Georgia, more people own firearms, and hence, carry a firearm with them when traveling by air. This is part of their personal gear, much like their smartphone. Inadvertently bringing their firearm with them when traveling by air is most likely an oversight for the majority of these people.  

To put this into context, there are on the order of 400 million firearms in the population. However, the demographics of gun owners provides a clue as to who is most likely to bring a firearm with them when traveling by air.  

Around one-third of the adult population owns a firearm. Men are more than twice as likely as women to own a firearm (46 percent versus 19 percent). The South has the highest gun ownership rate among adults (at 40 percent), which explains in part why Atlanta Hartsfield, Dallas Fort Worth International, and George Bush Intercontinental are the top three airports for firearms detected.  

These data are general numbers, and hence provide far too opaque an explanation for why people continue to bring firearms to airport security checkpoints. Most airports post large signs informing travelers to not bring their firearm with them when they reach the checkpoint. Yet in spite of such communication, firearms show up in passengers’ carry-on bags, with many loaded.  

The reality is that no detection procedures are 100 percent foolproof, which means that some firearms are passing undetected through airport security checkpoints. The good news is that none of these misses have resulted in an incident on airplanes or on the secure side of airports, based solely on media reports.  

This is largely due to the multiple security layers in place to protect the air system. No one layer must be completely airtight. What is needed is that they collectively provide an airtight secure air space.  

It’s now been over 22 years since 9/11; the TSA record suggests their security layers are achieving the desired objective.  

So even though a handful of flyers may pass through airport security carrying a firearm that is undetected, all the other layers in place have reduced their risk sufficiently to keep the air system secure.  

Think of the situation this way. Would you feel more secure on an airplane sitting next to a person carrying a gun who poses zero risk, like a law enforcement officer, or would you prefer to sit next to a known terrorist with malicious intent who does not have a weapon in their possession? Most people prefer the former person rather than the latter.  

The most advanced security layer, which does not involve physical detection of banned items, is Credential Authentication Technology coupled with biometrics, known as CAT-2. This somewhat innocuous looking technology is the TSA’s new weapon for securing the air system. This layer is the game-changer, and the TSA is going full throttle to deploy and advance this technology.  

What CAT-2 does is allow the TSA to know flyers better. Those with nefarious intent will do anything to hide their identity and intentions. CAT-2 provides a valuable layer of security to expose such people.  

So what more can the TSA and the airlines do to keep firearms out of airplane cabins?   

They could ask each passenger when confirming their identity if they have a firearm in their carry-on bag. This could prompt some to have their memory jarred and realize their oversight. If they say no, but a firearm is found, this should push the risk calculus higher. Asking this question will invariably reduce the number of firearms detected, since some travelers will confess their oversight.  

Alternately, the TSA and airlines could work together to offer passengers who wish to bring a firearm with them on their flight a secure hard case to be checked at no cost. Creating such a partnership may also reduce detected firearms, since some travelers will take advantage of this zero-cost option.  

As for the number of firearms that pass undetected that end up on airplanes, there is a simple way to estimate a lower bound for this number.   

Almost all travelers have a round trip itinerary. Of the 6737 firearms detected in 2023, how many were with travelers who were on the return portion of their trip? It is highly likely that they brought their undetected firearm with them on their originating flight as well.  

For example, on Dec. 15, 2023, a traveler from Georgia was caught at Reagan National Airport with a handgun in his bag . It is highly likely that this traveler was on the return part of their itinerary, and that the gun passed undetected during their originating flight.  

Looking forward to 2024, the TSA is highly likely to catch over 7,000 firearms, simply because there are more firearms in society and more people will be travelling. Yet the multiple layers of security deployed by the TSA ensure that when any one layer is breached, another layer is positioned to clean up the situation.  

Sheldon H. Jacobson, Ph.D., is a professor of Computer Science at the University of Illinois at Urbana-Champaign. He applies his expertise in data-driven risk-based decision-making to evaluate and inform public policy. He has studied aviation security for over 25 years, providing the technical foundations for risk-based security that informed the design of TSA PreCheck.