"We've had a series of reports actually going back several years from the inspector general, from the General Accounting Office, and our own TSA Office of Inspection, where they do, as you describe, covert testing," Pistole acknowledged to George Stephanopoulos last month during an interview on Good Morning America. "And unfortunately, [undercover testers] have been very successful over the years. And one of the findings is that we have not been thorough enough. And the concern obviously is, if that's an Abdulmutallab -- a Christmas Day bomber -- who is doing it rather than an undercover agent, then that can have catastrophic results."
For Seif, the discovery that he had accidentally carried a handgun on an international flight from Houston came as a shock. Rather than let the incident pass, he told ABC News he felt duty-bound to alert authorities to what he considered a gaping hole in security. When he met with Homeland Security officials upon his return to Houston, he said they appeared eager to remedy the problem.
"They were very embarrassed, you know," Seif said. "And -- and they should be, you know. It's -- we're talking about total failure."
TSA spokesman Greg Soule provided ABC News with a statement saying the agency was aware of the year-old incident and had taken steps to address it.
"We conducted an immediate investigation and remedial training was provided to the security officers involved," the statement said.
While it may seem odd for a traveler to walk into an airport with a gun in his carry-on luggage, Soule noted that it happens more often than most people think. Posted on TSA's web site is a count of handguns confiscated by screeners at security checkpoints each week. During the first week in December, screeners found 14 firearms, the website says.
But the agency will not comment on the performance by screeners in undercover testing. Homeland Security officials have determined that any details on performance at checkpoints could provide a road map for terrorists, said the TSA's Soule.
Sen. Charles Grassley, the Iowa Republican who called on the Government Accountability Office to conduct its own, independent covert tests of airport screening, decried the decision to classify the results as a national security secret.
"Those results aren't going to help terrorists figure out how to better attack us, and they certainly aren't going to give them any more motivation to try than they already have," Grassley said on the senate floor in September. "Keeping the results secret will accomplish one thing, however. It will ensure that the public has no idea how effective our airport screening strategy actually is."