Some people who carry handguns make the mistake of having those weapons in their bags when they fly. Some people are so used to carrying a gun, they literally forget it was there.

This can be a costly mistake. Having a weapon in your carry-on luggage or improperly in a checked bag is a federal crime, even if you did not have criminal intent. Here are answers to commonly asked questions about weapons and planes.

What if I have a legal permit to carry a gun?

It’s illegal to carry a weapon onto a plane even if you have a permit.

What if I had a weapon in my checked baggage?

You can carry unloaded firearms and ammunition in a locked hard-sided container as checked baggage. You must check your bag at the ticket counter and declare any firearms and ammunition.

What if I am a law enforcement officer?

While federal air marshals on duty status can carry weapons aboard aircraft, other state or federal officers cannot except in limited circumstances. For example, a police officer may be authorized by a government agency to bring a weapon aboard an aircraft for protective duty.

What are the penalties for bringing weapon into an airport?

You face civil penalties of up to $10,000, even if the violation was accidental. Depending on the circumstances, you could also face criminal charges.

Given the seriousness of the offense, you should contact an experienced criminal defense attorney if you are arrested for a handgun violation in an airport.