Air marshals monitor specific passengers

Federal air marshals have for years been quietly monitoring small numbers of U.S. air passengers and reporting on in-flight behavior considered suspicious, even if the fliers have no known terrorism links, the Transportation Security Administration said Sunday.

Under a sensitive, previously undisclosed program called “Quiet Skies,” the TSA has since 2010 tasked marshals to identify passengers who raise flags because of travel histories or other factors, and to conduct secret observations of their actions — including behavior as common as sweating heavily or using the restroom repeatedly — as they fly between U.S. destinations.

The Boston Globe revealed the existence of the Quiet Skies program on Sunday. In response to questions, TSA spokesman James Gregory offered more details of the program’s origins and goals, likening it to other law enforcement activities that ask officers to closely monitor individuals or areas vulnerable to crime.

“We are no different than the cop on the corner who is placed there because there is an increased possibility that something might happen,” Gregory said. “When you’re in a tube at 30,000 feet ... it makes sense to put someone there.”

The TSA declined to provide complete information on how fliers are selected for Quiet Skies scrutiny and how the program works.

According to the TSA, the program used travel records and other factors to identify passengers who will be subject to additional checks at airports and, sometimes, be observed in flight by air marshals who report on their activities to the agency.

Gregory said the program did not single out passengers based on race or religion and should not be considered surveillance because the agency does not, for example, listen to passengers’ calls or follow flagged people around airports.

But during in-flight observation of people who are tagged as Quiet Skies passengers, marshals use an agency checklist to record behavior: Did he or she sleep during the flight? Did he or she use a cellphone? Look around erratically?

Gregory declined to say whether the program has resulted in arrests or disruption of a criminal plot.