IN GENERAL.—The Under Secretary of Transportation for Security may take the following actions:
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(7) Provide for the use of voice stress analysis, biometric, or other technologies to prevent a person who might pose a danger to air safety or security from boarding the aircraft of an air carrier or foreign air carrier in air transportation or intrastate air transportation.

The Administrator of the Transportation Security Administration shall provide advanced training to transportation security officers for the development of specialized security skills, including behavior observation and analysis, explosives detection, and document examination, in order to enhance the effectiveness of layered transportation security measures.

The identification policy requires that airline passengers either present identification or be subjected to a more extensive search. The more extensive search is similar to searches that we have determined were reasonable and "consistent with a full recognition of appellant’s constitutional right to travel." United States v. Davis, 482 F.2d 893, 912-13 (9th Cir. 1973).

In Davis, an airline employee searched the defendant’s briefcase as part of the airport’s preboarding screening procedure.... we held that airport screening searches of potential passengers and their immediate possessions for weapons and explosives is reasonable so long as each potential passenger maintains the right to leave the airport instead of submitting to the search. Id. at 912. In so holding, we considered several airport screening procedures, including behavioral profiling, magnetometer screening, identification check, and physical search of the passenger’s person and carry-on baggage. Id. at 900. We see little difference between the search measures discussed in Davis and those that comprise the "selectee" search option of the passenger identification policy at hand. Additionally, Gilmore was free to decline both options and use a different mode of transportation. In sum, by requiring Gilmore to comply with the identification policy, Defendants did not violate his right to travel.

Beginning in October 1968, a Federal Aviation Administration task force, including representatives of the Department of Justice and the Department of Commerce, compiled a "profile" of objective characteristics to identify potential hijackers. In December 1968, the Federal Aviation Administration held an intensive high-level symposium on the development of devices for the screening of individuals for possession of concealed weapons. The FAA Task Force, working in cooperation with the carriers, then developed the initial anti-hijacking "system."

Although the specific elements varied over a period of time, the system generally included, first, the use of the "profile," next, the use of a magnetometer to detect the presence of metal on any prospective passenger who met the "profile," and finally, a weapons search of the carry-on luggage and/or person of anyone who activated the magnetometer.

The FAA and the airlines worked together to put the system into operation at the nation's airports. As a part of this cooperative effort, United States deputy marshals and Customs Service agents were made available to carry out searches and make arrests. By September 1970, approximately 400 United States deputy marshals were assigned to surveillance and search activities at airport boarding gates....

On February 1, 1972, the FAA issued a rule requiring air carriers to adopt and put into use within 72 hours a screening system "acceptable" to the FAA "to prevent or deter the carriage aboard its aircraft of sabotage devices or weapons in carry-on baggage or on or about the persons of passengers." This system was to require the screening of all airline passengers "by one or more of the following systems: behavioral profile, magnetometer, identification check, physical search."
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On August 1, 1972, the FAA issued a directive that no airline "shall permit any person" meeting the profile to board a plane unless his carry-on baggage had been searched and he had been cleared through a metal detector or had submitted to a "consent search" prior to boarding. On December 5, 1972, the FAA ordered that searches of all carry-on items and magnetometer screening of all passengers be instituted by January 5, 1973. Routine screening and searching under this procedure was to be conducted by airline personnel, but in the presence of armed law enforcement officers "(1) Authorized to carry and use firearms," and "(2) Vested with a police power of arrest under Federal, State, or other political subdivision authority.

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It makes no difference that the act of opening appellant's briefcase was accomplished by a "private" airline employee rather than a "public" official. The search was part of the overall, nationwide anti-hijacking effort, and constituted "state action" for purposes of the Fourth Amendment.

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[T]he need for some limitations upon these rights [the passenger's right to travel and right to personal privacy] is clear. In light of that need, a screening of passengers and of the articles that will be accessible to them in flight does not exceed constitutional limitations provided that the screening process is no more extensive nor intensive than necessary, in the light of current technology, to detect the presence of weapons or explosives, that it is confined in good faith to that purpose, and that potential passengers may avoid the search by electing not to fly.