Updated

There is almost certainly a pattern in the Washington-area sniper shootings. Finding it is the devilish detail.

More than two weeks of frantic investigation and even more harried speculation have kicked up a storm of leads, theories, odd facts and false twists -- a mountain of meaninglessness that may contain telling information if it ever gets sorted out.

"Yes, there is a pattern but whether it's one that can be easily discerned is another matter," says Iain Murray, an authority on statistics. "We're talking about human beings and there's always some sort of rationality behind them.

"Unless," he went on, "he's a dice man -- deliberately being random by rolling dice and acting according to the roll."

Certain noticeable patterns in the sniper case were thrown into question Saturday night when a man was shot and wounded outside a restaurant in Ashland, Va., near Richmond.

Police were not sure the attack was the work of the sniper, but assumed so. It would have been his first shooting on a weekend and was much farther from Washington than the rest.

Ashland is 85 miles south of Washington along Interstate 95; Fredericksburg, where two sniper shootings have happened, is in the same direction, about 50 miles from the capital.

The shooting bore some trademarks of the sniper: a single shot from a distance, a commercial rather than strictly residential area, the apparently random choice of a victim, a quick getaway before roads were sealed.

Geographic profilers, who use computer grids and their own logic to try to figure out where a serial killer lives or works based on where he shoots, have said the sniper must be following a geographical pattern because such killers do.

It's just that they don't know what it is.

Generally, they believe criminals of his type operate in an area familiar to them, but not too close.

A geographical pattern was claimed by the man accused of putting 18 pipe bombs in rural mailboxes in May, wounding six people. He said he was trying to make a smiley face over five states. Authorities didn't see it and didn't know whether to believe it when told.

The bombs were arranged in circles resembling eyes and what could have been the start of a mouth.

In the sniper case, police have given the public little to go on. They have released sample images of a white box truck and white or very light Chevrolet Astro and Ford Econoline vans -- possible getaway vehicles. They have not ruled out multiple killers.

The first of 12 shootings firmly linked by police happened Wednesday, Oct. 2, when a gunshot harmlessly pierced a window at a Michaels craft store in Montgomery County, Md. About 45 minutes later, James D. Martin, 55, fell dead in a nearby grocery store parking lot, the first known sniper victim.

Four people in the county were killed the next morning, one that evening just across the line in Washington. After that the killer began mixing up locations in the course of wounding two people and killing four more before a lull that followed a slaying in Falls Church, Va., on Monday night.

"Eventually you fall back into a pattern," said Tod W. Burke, a criminal justice scholar at Radford University in Virginia. "He's trying his best not to create a pattern, but he's got a pattern."

The danger is being diverted by a wrong or nonexistent one.

"It's all too easy to put things together and find a pattern that could be misleading," said Murray, research director for the Statistical Assessment Service, which analyses science and statistics in public affairs. "We all want to be Sherlock Holmes."

Among the theories:

-- That he has begun reacting to police and other public officials. All but two of the shootings have been at well-defined commercial areas -- shopping centers or gas stations. But he wounded a boy dropped off at school, right after a weekend during which the public was assured that children had not been targeted and would be kept safe while at school.

His attacks have grown, if anything, more audacious even as public figures have branded him a coward and as commentators have sniffed about his marksmanship. He shot Kenneth H. Bridges, 53, at a Fredericksburg gas station Oct. 11 despite the presence of a policeman nearby, and he shot Linda Franklin, 47, three days later in a parking lot by a busy Falls Church intersection.

-- That he has a job with weekend hours or is otherwise engaged on weekends -- a theory that comes apart if the Ashland shooting is linked.

His morning weekday attacks have been from 7:41 a.m. to 9:58 a.m. Only one attack has been in early afternoon, 2:30 p.m. The rest have been from 5:20 p.m. to 9:15 p.m.

-- That there is significance in the fact that his first shooting was at a Michaels store and that other stores in the chain are near most of the crime scenes -- as are many outlets of other franchises.

"Part of the problem with statistics and probability is that a lot of things are very common; you just don't notice them," Murray said.

White panel vans with ladders or ladder braces, for example. They are the choice of tradesmen and they're everywhere.