These changes have been overseen by the Transportation Security Administration (TSA), the federal agency created in the aftermath of the 9/11 terrorist attacks under provisions in the Aviation Transportation and Security Act (ATSA; P.L. TSA has responded to such criticisms by attempting to shift from an approach that assumes a uniform level of risk among all airline travelers to one that focuses on passengers thought to pose elevated security risks. What Is Risk? There is no perfect security." Risk-based passenger screening includes a number of initiatives that fit within this broader framework, but it focuses specifically on detecting and managing the threat element of risk. Risk-Based Approaches Applied to Airline Passengers

Risk-based approaches to airline passenger screening have been used since the early 1970s. As initially envisioned, CAPPS II was to integrate checks of passenger name records against the "no fly" list of individuals to be denied boarding and the "selectee" list of individuals of elevated risk requiring more thorough secondary screening. Pre-Screening International Passengers

Secure Flight development benefited from operational experience with the Advance Passenger Information System (APIS) administered by U.S. Customs and Border Protection (CBP), which predated Secure Flight and continues to collect passenger manifest data from airlines for all international flights inbound to the United States. CBP also relies on its Automated Targeting System-Passenger (ATS-P) to perform risk assessments on inbound and outbound international travelers. A separate TSA program, Screening Passengers by Observational Techniques (SPOT), attempts to identify passengers who could present threats by observing behavior at airports. The Pre-Check Program

While behavioral detection approaches have been sharply criticized, TSA's efforts to implement Pre-Check, a trusted traveler program designed to expedite processing of low-risk passengers, have garnered more favorable responses. New passenger screening canine teams, specially trained to work in crowded areas and sniff passengers to detect the scent of explosives, along with behavioral detection officers who screen individuals for behavioral indicators of potential threat, perform initial screening of passengers in the screening checkpoint queue. In summary, as TSA moves forward in its implementation of a risk-based approach to passenger screening, questions persist as to whether this approach
appropriately integrate s various programs and elements of the approach and interdependently and collectively exhibits the characteristics of a comprehensive risk-based strategy outlined in Table 1 ; adequately adapt s and evolve s to changes in the threat landscape, to potential changes in the availability of resources including personnel, and to the introduction of new procedures and technologies; can identify and analyze appropriate metrics for assessing the effectiveness of risk-based programs against specific mission goals tied to detecting and mitigating threats to civil aviation; adequately addresses potential impacts of false positives without compromising threat detection capabilities; and ensures appropriate privacy and data protections consistent with those detailed in the agency's SORNs and in a manner that appropriately balances security and intelligence needs with public expectations.
Until recently, the Transportation Security Administration (TSA) had applied relatively uniform methods to screen airline passengers, focusing primarily on advances in screening technology to improve security and efficiency. TSA has recently shifted away from this approach, which assumes a uniform level of risk among all airline travelers, to one that focuses more intently on passengers thought to pose elevated security risks. Risk-based passenger screening includes a number of initiatives that fit within a broader framework addressing security risks, but specifically emphasizes the detection and management of potential threats posed by passengers.
Various risk-based approaches to airline passenger screening have been used since the early 1970s, including the application of rudimentary behavioral profiles, security questions, and analysis of ticket-purchase data to look for indicators of heightened risk. Additionally, "no-fly" lists were developed to prevent known or suspected terrorists from boarding aircraft, but prior to the terrorist attacks on September 11, 2001, these lists were not robust and proved ineffective.
Following the 9/11 attacks, TSA's initial risk-based efforts focused on integrating checks of passenger name records against the "no fly" list of individuals to be denied boarding and the "selectee" list of individuals of elevated risk requiring more thorough secondary screening. These efforts culminated in the deployment of Secure Flight, which screens each passenger's full name and date of birth against terrorist watchlists. Additionally, international passengers are screened by U.S. Customs and Border Protection (CBP), which uses the Advance Passenger Information System (APIS) and the Automated Targeting System-Passenger (ATS-P) to conduct risk assessments.
At airports, TSA employs behavioral detection and analysis under the Screening Passengers by Observational Techniques (SPOT) program in an effort to identify suspicious passengers. Another risk-based security program is Pre-Check, a trusted traveler program designed to expedite processing of low-risk passengers. In addition to the Pre-Check participants, TSA is routing certain other passengers through expedited lanes using behavior detection officers and canine teams to screen for suspicious behavior and explosives under an initiative called managed inclusion.
Implementation of risk-based passenger screening raises numerous issues of congressional interest. These include the efficacy of the SPOT program; how the various elements and programs complement each other and integrate with TSA's other layers of security; the risk-based approach's ability to adapt and evolve over time; the ability to measure its effectiveness; the potential impacts of false positives on the traveling public; and implications for safeguarding data and maintaining privacy.