As the search for the Washington, DC sniper continues, speculation arose that the gunman was an al Qaeda terrorist. On the one hand, sniping and marksmanship were never emphasized during al Qaeda training. They tended to promote massive fire power (full auto on AK-47s plus firing RPG rockets at the same time.) But al Qaeda did stress a wide range of possible attacks, and it is certainly possible that an al Qaeda member could have figured out that sniper training material found on the web provided an excellent opportunity to terrorize the Washington DC area. What the DC sniper has done so far is basically sniping 101. That is, the sniper carefully scouts the target area and selects a place to fire one shot and then get away. Military snipers are taught to find a hidden position with several escape routes. If the sniper is operating in an area with lots of enemy troops around, one tactic is to take just one shot, and then move. Suburban Washington provides ample opportunities to do that. The ring of roads and suburbs surrounding 

Washington is built for cars, not pedestrians. A sniper need only find places where he can park, open his car window or door, wait for a victim to move into view some 50-100 meters away, and then take the shot. With a $400 dollar .223 caliber, bolt action rifle (and scope), a shooter with a few hundred rounds of practice shots should be able to his the target 90 percent of the time, which is what the DC sniper has done. Once the sniper has fired, he (or an accompanying spotter/driver) starts moving the car towards one of the several escape routes previously scouted. There will be a few minutes before the police will know someone has been shot, and so far that has been enough for the sniper to get away. 

While much has been made about a "white van," al Qaeda training does teach terrorists how to use false ID for things like credit card fraud (for renting cars.) Moreover, you can get .223 rifles that can be broken down to fit in a brief case, so no one will see the sniper getting into a car or van with what looks like a rifle. 
An al Qaeda member on a "jihad" (suicide) mission would find a sniping campaign in a suburban area very satisfying. The biggest risk would be getting captured and put away in a federal prison for life. Recruiting for al Qaeda would be a lot harder if "jihad" was interpreted as "life without parole." However, the fact that al Qaeda has not taken credit for these shootings, and the fact that there are 15-20 sniper killings a year in the United States, indicates that this is just another demented serial killer.

There are limitations on this kind of terrorism, no matter who is responsible. You can't really expect to get away with it in densely populated areas with lots of pedestrians. Trying this in a place like downtown DC, or Manhattan, confronts the sniper with a lot more witnesses (which, in New York City, can quickly turn into an angry posse) and fewer escape routes. 

Earlier reports that a British Islamic organization, Sakina Security Services, was providing training for snipers in at Ground Zero, an Alabama training camp, proved to be false. When the people running Sakina Security Services were put on trail this past summer, they were acquitted. One reason was that testimony revealed that only one person had signed up for the Alabama training camp program, and he was a security guard from London. At one point before the trail, the media was going on about "1,800 and 2,000 British Muslims were going abroad each year for military training." This proved to be untrue. Apparently some 500 British Moslems did go overseas for some military training, mostly in Afghanistan and Pakistan. But sniping was not a major part of that training.

But you don't need a professional course of training to become a sniper. You can buy a .223 caliber rifle and scope second hand for under $300. Ammo costs as little as twelve cents a round (or less). If you can get out to a rifle range, or a lightly populated area in Virginia or West Virginia, you can fire off a hundred dollars worth of ammo and become skilled enough to kill civilians standing still at ranges of about a hundred meters or less. The DC sniper isn't a master marksman, just a careful killer. And even if the goal of the sniper isn't terror, millions of people in the DC area are terrorized.