Research Suggests Body Scanners Easy to Fool

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Two professors at the University of California, San Francisco, claim beating the TSA’s body scanners is easy. In a lengthy (and science-heavy) report, they conclude that some explosives and small weapons can be concealed in such a way that the scanner, or human screener, does not pick them up.

Basically, if you take the explosive PETN, which was used in the Christmas Day bombing attempt last year, and compress it into a thin sheet, that sheet, placed over the abdomen, could be invisible to the scanner. Or, as the report puts it:

“It is very likely that a large (15–20 cm in diameter), irregularly-shaped, cm-thick pancake with beveled edges, taped to the abdomen, would be invisible to this technology, ironically, because of its large volume, since it is easily confused with normal anatomy. Thus, a third of a kilo of PETN, easily picked up in a competent pat down, would be missed by backscatter ‘high technology’. Forty grams of PETN, a purportedly dangerous amount, would fit in a 1.25 mm-thick pancake of the dimensions simulated here and be virtually invisible. Packed in a compact mode, say, a 1 cm × 4 cm × 5 cm brick, it would be detected.”

Yes, that’s a bit scary to read, though as Umar Farouk Abdulmutallab showed last year, getting PETN, or any explosive component onto an aircraft, is only half the battle. But while PETN is sometimes difficult to detonate (as Abdulmutallab duly demonstrated), it has nevertheless become terrorist’s explosive component of choice, appearing in both the 2001 shoe bomb attempt and October’s cargo plane/toner cartridge scheme, along with Abdulmutallab’s failed underpants plan. None of this is to say that circumventing the scanners is as simple as rolling out a pie-crust-sized slab of explosives and waltzing onto the plane, either. The report is simply saying that, if done correctly, this method could fool the scanner.

The report also suggests thin wires may be missed by the machines, and small hand weapons concealed along the side of someone’s body may not be apparent to the scanner or its human screener.

Depressing as this news is, considering the expense and controversy surrounding the scanners, I’d rather have a pair of professors identify the scanners’ weaknesses than a bunch of terrorists. And quite frankly, no one should be surprised to learn that the scanners can be circumvented. That’s the game the TSA is in: An evolving war of strategies. For every brilliant defense the TSA conjures up, there is an equally brilliant—but, one hopes, exceedingly difficult—way around.

Whether or not you agree with the TSA’s methods, of course, is another matter entirely.