[livius]

I wondered about the possibility of hiding in a bigger truck, too (that is, driving into one), although then I couldn't see how they could do this without being noticed.

The people doing this are enormously familiar with the area roads. I'm sure they've probably been employed in some capacity that involved a lot of driving, or are perhaps independent taxi drivers who might be very familiar with the area and are not under supervision by an employer (I can't imagine any employer who owns a white truck like this not noticing that it was being sought in this case!)

[Mamzelle]

If this is Islamic terrorism, perhaps there's some garage doors open for them, complete with door remotes. Fanciful...I guess...but it wouldn't be that complicated to do.

[angkor]

The people doing this are enormously familiar with the area roads.

Excellent point. Your mention of a cabbie also answers some questions.

Since there are probably two, its likely the driver is very knowledgeable about DC Metro roads, and not just the highways. He knows traffic patterns and methods of escape and how to plan a shooting for both impact and easy egress.

He knows how the traffic flows in different parts of the area, maybe even a few shortcuts around traffic "chokepoints." Obviously quite an experienced driver, not some newbie to the area (his whole pattern seems almost diabolically knowledgeable).

And it wouldn't be merely a local DC or Virginia cabbie, but someone who drives all around the metro area, for example an airport cabbie. If he serviced National DCA, he'd be in just about every suburban area so far targeted by the shooter: Manassas, Bowie, Falls Church, Kensington. The Fredericksburg shootings don't add up, but I suppose its possible someone might take an airport cab to/from there.

On the other hand the shooter is probably the al Qaeda import, probably not at all familiar with the roads, but experienced with killing.

I've been wondering from the outset how these guys knew so much about the roads and traffic. Airport cabbie make a great deal of sense.

I suppose its obvious, but most DC airport cabbies are not white male ex-Marine sharpshooters with NRA memberships.