Since the 9-11 attacks, American airports have taken steps to keep travellers safe.
But significant vulnerabilities remain.
The attack that killed five people Friday at the Fort Lauderdale airport raises concerns about how to further protect travellers and what place firearms have in U.S. airports.
Authorities say Iraq war veteran Esteban Santiago retrieved a handgun from his checked luggage, went to a bathroom to load it and then returned to the baggage claim area to open fire.
Transportation security and law enforcement experts say the baggage claim area remains one of the most vulnerable parts of the airport.
Security is lighter and large numbers of people move in and out quickly.
Santiago's been charged with an act of violence at an international airport resulting in death, along with weapons charges.
He faces the death penalty if convicted.
He's scheduled to appear in court on Monday.