The Transportation Security Agency has a costly and growing program to spot air travelers behaving in a suspicious manner. Its name is SPOT, for “Screening of Passengers by Observation Techniques.”

It is, however, more like a blot on the air travelers’ landscape. Not to mention a lot of red ink for the TSA and the taxpayer.

To put it bluntly, the Homeland Security Department’s Inspector General says that the TSA cannot prove that SPOT really works.

The TSA has spent nearly a billion dollars on SPOT since 2007, hiring 2,800 employees to cast a gimlet eye on passengers in security lines in an effort to spot those who seem to be under stress. USA Today reports that the screeners look for “shifty eyes” and “sweating.” They pull aside passengers for further questioning, with meager results.

Just because a passenger is fidgety and perspiring while queuing up in the TSA cattle maze doesn’t make him a dangerous person. Some people are simply nervous about the prospects of flying, or getting a government-ordered X-ray or making it to the flight gate on time.

From October 2011 to September 2012, an estimated 657 million passengers boarded aircraft in the United States. Of this vast number, SPOTters recorded pulling aside 37,370 passengers, resulting in 199 arrests, typically for outstanding warrants, suspected drugs and immigration status. The program did not record the number of passengers who were not allowed to board an aircraft.

The SPOT program cost an estimated $200 million that year, resulting in an average cost per arrest of about $1 million.

Small wonder that Homeland’s inspector general found the program could not show that it was cost-effective, much less justify a planned expansion.

He also reported that “TSA did not (1) assess the effectiveness of the Screening of Passengers by Observation Techniques program, (2) have a comprehensive training program, (3) ensure outreach to its partners, or (4) have a financial plan.”

The TSA says it has taken all the steps recommended by the IG to improve the SPOT program, which it considers “a critical part of our approach to securing travel.” But in an appendix on training, the IG’s office notes that SPOT personnel are supposed to learn and apply a ridiculous 63,321 possible combinations of behavioral factors that could lead to pulling a passenger out of line for questioning.

Meanwhile, some TSA officers have been accused of racial profiling.

The TSA should be required to concentrate its resources on programs that actually work. See SPOT run, and disappear.