ON JANUARY 6th, a gunman ran amok at Fort Lauderdale-Hollywood International Airport, killing five people. Earlier this week, Esteban Ruiz Santiago, a 26-year-old Iraq war veteran, appeared in court charged in relation to the horrific crime. If convicted, the judge told him, he could face the death penalty.

Mr Santiago allegedly pulled a gun out of his luggage in the baggage reclaim area. Although he appears to have a history of questionable mental behaviour, including entering an FBI building with a magazine of ammunition, he had probably checked his weapon into the hold of his flight legally. According to Transport Security Administration (TSA) rules, “You may transport unloaded firearms in a locked hard-sided container as checked baggage only. Declare the firearm and/or ammunition to the airline when checking your bag at the ticket counter. The container must completely secure the firearm from being accessed.”

Yet despite such an easy-going attitude to allowing passengers legitimately to fly with guns, an increasing number try to do so illegally, by sneaking firearms onto planes in their carry-on luggage. Figures released this week by the TSA show that 3,391 such weapons were found by security staff in 2016. That number has been rising steadily for years (see chart). Eighty-three per cent of these guns are loaded.