The deadly shooting at a Florida airport on Friday is likely to rekindle an ongoing debate over whether screening systems should be even more exacting.
But experts say preventing attacks like the one on Friday, when a gunman opened fire in a baggage claim area at Fort Lauderdale-Hollywood International Airport, is almost impossible given the large public areas at U.S. airports, despite the billions of dollars spent on security.
"To the extent it was not in a secure area, it doesn't really identify any issues around airport security," said Robert Mann, an aviation consultant. "A guy walks into a bar, a guy walks into an airport baggage claim room - neither of them are secure."
Friday's attack killed five people and injured at least eight, authorities said.
Security at most major airports worldwide is generally focused on protecting aircraft from potential attackers and deadly devices, rather than the airports themselves. As a result, much of the space at terminals is easily accessible to the public, with no formal screening before passengers go through checkpoints to get to their departure gates.
The debate over whether to extend security screening to public areas intensified following the bombings inside a terminal at Brussels Airport in March 2016, which killed 32 people and injured hundreds.
Some critics have cited as a model Israel's Ben Gurion Airport, where private security companies trained by the national security agency Shin Bet and backed by police officers profile passengers, question individual travelers and use bomb detectors at the airport's entrance.
But experts say that approach has drawbacks, possibly just shifting the target to another part of the airport.
"It is logistically impractical to try to protect these areas, unfortunately, and the reason is no matter how far you move the boundary out, you will always have some sort of soft target area," Henry Harteveldt, an airline industry analyst, said.
The cost of implementing that type of screening would also be prohibitive, given the number of major U.S. airports.
In response to the Florida shooting, law enforcement agencies at several U.S. airports said they beefed up security presence, including in Chicago and New York.
Friday's shooting, in which the gunman apparently retrieved a checked gun from his luggage, loaded it in a bathroom and then opened fire, could prompt debate about whether travelers should be permitted to stow guns in checked bags, Harteveldt said.
Addressing one potential danger often simply creates an opportunity for another type of threat, Mann said.
"It's essentially whack-a-mole," Mann said. "That's what security has always been."