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Aviation Security: TSA Should Limit Future Funding for Behavior Detection Activities

GAO-14-158T Published: Nov 14, 2013. Publicly Released: Nov 14, 2013.
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What GAO Found

In November 2013, GAO reported that (1) peer-reviewed, published research we reviewed did not support whether nonverbal behavioral indicators can be used to reliably identify deception, (2) methodological issues limited the usefulness of DHS's April 2011 SPOT validation study, and (3) variation in referral rates raised questions about the use of indicators. GAO reported that its review of meta-analyses (studies that analyze other studies and synthesize their findings) that included findings from over 400 studies related to detecting deception conducted over the past 60 years, other academic and government studies, and interviews with experts in the field, called into question the use of behavior observation techniques, that is, human observation unaided by technology, as a means for reliably detecting deception. The meta-analyses GAO reviewed collectively found that the ability of human observers to accurately identify deceptive behavior based on behavioral cues or indicators is the same as or slightly better than chance (54 percent). GAO also reported on other studies that do not support the use of behavioral indicators to identify mal-intent or threats to aviation.

GAO found that DHS's April 2011 validation study does not demonstrate effectiveness of the SPOT behavioral indicators because of methodological weaknesses. The validation study found, among other things, that some SPOT indicators were predictive of outcomes that represent high-risk passengers, and that SPOT procedures, which rely on the SPOT behavioral indicators, were more effective than a random selection protocol implemented by BDOs in identifying outcomes that represent high-risk passengers. While the April 2011 SPOT validation study is a useful initial step and, in part, addressed issues raised in GAO's May 2010 report, methodological weaknesses limit its usefulness. Specifically, as GAO reported in November 2013, these weaknesses include, among other things, the use of potentially unreliable data and issues related to one of the study's outcome measures.

Why GAO Did This Study

This testimony discusses GAO's November 2013 report assessing the Department of Homeland Security (DHS) Transportation Security Administration's (TSA) behavior detection activities, specifically the Screening of Passengers by Observation Technique (SPOT) program. The recent events at Los Angeles International Airport provide an unfortunate reminder of TSA's continued importance in providing security for the traveling public. TSA's behavior detection activities, in particular the SPOT program, are intended to identify high-risk passengers based on behavioral indicators that indicate mal-intent. In October 2003, TSA began testing the SPOT program, and by fiscal year 2012, about 3,000 behavior detection officers (BDO) had been deployed to 176 of the more than 450 TSA-regulated airports in the United States. TSA has expended a total of approximately $900 million on the program since it was fully deployed in 2007. This testimony highlights the key findings of GAO's November 8, 2013, report on TSA's behavior detection activities. Specifically, like the report, this statement will address (1) the extent to which available evidence supports the use of behavioral indicators to identify aviation security threats, and (2) whether TSA has data necessary to assess the effectiveness of the SPOT program in identifying threats to aviation security.

For more information, contact Steve Lord at (202) 512-4379 or

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