Despite expensive and inconvenient measures adopted after the 9/11 attacks to make airplanes safer, airports remain as vulnerable as any other public place to someone with a grudge, a weapon and a statement to make.
The Los Angeles International Airport shooting is unlikely to change that, many security experts agree.
Although it's almost impossible to get on a plane with a bomb or gun, there's neither the will nor the funds to similarly protect airport parking lots, curbsides, lobbies, ticket counters and baggage claims.
Despite the shooting, "airport security is going to be pretty much what you've got now,'' predicts Joe King, a former Customs agent and Department of Homeland Security official who teaches at John Jay College of Criminal Justice in New York.
The issue was revived after a gunman opened fire inside LAX's Terminal 3 on Friday, killing one Transportation Security Administration officer and wounding four other people, two of them TSA workers.
The 23-year-old alleged gunman told authorities at the scene he acted alone and had been dropped off at the airport by a friend, a law enforcement official who has been briefed on the investigation told The Associated Press on Sunday.
Authorities do not believe the friend knew that Paul Ciancia, the man charged in the attack, planned to open fire moments later, said the official, who is not authorized to speak publicly about the investigation and requested anonymity.
Ciancia was dropped off in a black Hyundai and was not a ticketed passenger. He was able to respond to investigators' questions at the scene Friday, the source said.
Ciancia, an unemployed motorcycle mechanic who grew up in the small, working-class town of Pennsville, New Jersey, was shot four times and was under 24-hour armed guard at the hospital, the official said.
Federal prosecutors charged Ciancia on Saturday with murder of a federal officer and committing violence at an international airport. The charges could qualify him for the death penalty.
The union representing TSA airport screeners says the shooting shows the need for armed security officers at every checkpoint. The TSA says it expects no immediate change in overall security policy but that "passengers may see an increased presence of local law enforcement officers throughout the country."
For how long? King says that when it comes to airport security - especially the vast areas outside the TSA-protected secure perimeter -- costs are huge and payoffs only occasionally visible - "and so it's hard to justify to the budget people.''
Paul Ekman, a psychologist whose research in facial expressions helped shape the TSA program to spot potential offenders, has criticized the government's failure to extend the program to all feeder airports. Asked what impact the LAX shooting would have on security at other airports around the nation, he said, "I don't think it'll change a thing.''
Security experts make these points:
• Airport security is really designed for airplanes. That's as it should be, says Stewart Baker, former Department of Homeland Security policy director, given al-Qaeda's fixation on attacking flights and the public's sensitivity to air travel disaster.
On the other hand, he says, an airport public area "is only one of 50 places where Americans congregate in numbers,'' including the main concourse of Grand Central Terminal in New York City, which people can enter and leave dozens of ways without passing through a detector or past a police officer.
The key is not controlling such spaces, but observing them, Ekman says. At airports in Israel and the United Kingdom, surveillance starts as soon as the traveler steps from the car, the bus or the train.
• Extending airport security outside TSA-manned checkpoints is very expensive and rarely necessary. The commander's dilemma: Assigning officers to checkpoints leaves the rest of the terminal more vulnerable.
The TSA approves each airport's security plan, which is then executed by the airport, either through its own force with local police.
King says airport police forces are designed primarily "to move traffic.'' As such, "they're a traveling police force, rather than based at fixed posts'' such as security checkpoints, he says. When there's an emergency, officers usually must be called to the scene, a process that can take several minutes.
Even if TSA checkpoints were protected by armed officers and public areas outside the perimeter more tightly controlled, patrolled or observed, "then it becomes, 'Where are they going to hit instead?''' he says of potential attackers.
• Arming TSA checkpoints, whatever its effectiveness in stopping or deterring attacks, would be expensive and contentious. The TSA workers' union has not requested they be armed. If they were, King says, they'd expect to be paid like police officers, with bigger salaries and pensions. A more likely outcome, he says, might be arming some TSA supervisors at a limited number of airports.
That and a range of other moves might encounter resistance in Congress, where some members have criticized TSA techniques for searching travelers.
U.S. Rep. John Mica, R-Fla., chairman of a House committee with broad scope and subpoena power, favors returning airport screening to private companies. But J. David Cox Sr., president of the American Federation of Government Employees, the union that represents TSA workers, says the LAX shooting proves the need for a federal force to screen travelers.
Contributing: Bart Jansen, Associated Press