Transportation Security Administration (TSA) officers seized a firearm that was “artfully concealed” inside of a passenger’s shoe at Philadelphia International Airport last week.

The .25 caliber handgun was discovered unloaded at a security checkpoint on September 23. The weapon was confiscated and the Philadelphia man was arrested by local police.

“Our TSA officers are skilled at detecting firearms and other prohibited items,” Gerardo Spero, TSA’s Federal Security Director for PHL, said in a statement. “This was not a case of forgetfulness. This was an intentional effort on the part of this individual to try to board an airplane with a gun. Not only will he need to spend money on an attorney as a result of his arrest but he now faces a stiff federal financial civil penalty.”

TSA reminds travelers that the typical first offense for carrying a loaded handgun into a checkpoint is $4,100 and can reach as high as $13,669 depending on the circumstances.

The gun was the 18th intercepted by TSA officers at the airport this year. Officers uncovered 20 firearms total at PHL in 2019. What’s more, last Wednesday’s incident occurred during TSA’s Prohibited Items Week, during which the agency made it a point to remind travelers about the items they can and can’t pack in their carry-on.