I guess the same way we tell if that car zooming at a militry check-point and ignoring all signals to stop is an Italian Journalist or a VBIED.

of course you can't. got to be careful, in life. things can go wrong in the blink of an eye.

We don't know now, but for about 3 trillion in government research money I'm sure we can come up with a gizmo the size of a volkswagen and a pricetag under one mil each that can tell.

Or you can wait five minutes and check for holes.

Those agents did the right thing all the way down the line.

Good for them.

One good thing that's come out if this is that now everybody knows for certain that there are air marshals on planes (sometimes even 2). And that they will quickly and decisively do what's necessary.