Siege mentality intensifies as suburban killer stays silent

Amid increasing desperation to uncover a real lead in the hunt for the Washington serial sniper, detectives were yesterday examining a shell casing found in a white van similar to the kind of vehicle sought by police.

The casing was found in a box truck on Friday by staff at a car rental agency near Dulles International Airport, close to where many of the 12 shootings have taken place. At the same time, officers have charged a man who gave a detailed description of the most recent fatal shooting after concluding that he had invented his account.

The shell casing is one of just a handful of possible leads that detectives have to go on more than two weeks after the sniper began the series of shootings that have killed nine people. Results of tests being carried out by the Bureau of Alcohol, Tobacco and Firearms laboratory could be known today.

Officers had hoped that the details provided by Matthew Dowdy, 37, who told them he had watched as the gunman killed Linda Franklin while she loaded her car at a Home Depot DIY store last Monday, would be a breakthrough. After Mr Dowdy spoke with police, officers released a description of an olive-skinned man leaving the scene in a cream-coloured Astro van with a faulty tail-light.

But officers now believe Mr Dowdy had been inside the store at the time of the shooting and saw nothing of value. He has been charged with making a false statement to police and faces a maximum of six months in jail. "What he did was outrageous," said Robert Horan, the Virginia state prosecuting attorney.

Amid such farce and frustration, much of the Washington area remains in a mental state of siege as people struggle to make themselves feel secure.

Dinner-table conversation concentrates on what sort of person the sniper is, while at petrol stations people pump fuel while literally on their knees as they try to present as low a profile as possible. In the suburbs people report shoppers walking down the street in a zig-zag, as recommended by police.

Many arts and sports events around Washington have remained cancelled this weekend. Even pumpkin sales have been hammered in the run-up to Hallowe'en as the sniper threatens to put a serious damper on trick-or-treating

Bizarrely, what has added to the tension is the fact the sniper has not struck for six days – the longest gap since the shooting spree started – leaving people wondering which suburban location might be next. While police say that every day without a shooting is a good day, they also know that they have more chance of catching the killer if he strikes again.

With so little to go on, investigators have turned to avenues of inquiry that initially seemed fruitless. It has emerged that US interrogators at Guantanamo Bay have started asking Taliban and al-Qa'ida prisoners if they have any information about the gunman. Officials stress this has been done to cover all investigative bases rather than from any hard evidence that al-Qa'ida is involved.

What many here cannot understand is why no one has come forward with information about the killer. With the reward now standing at $500,000, people wonder why no one has made that all important call to the police. The answer may be that the sniper is acting alone and leaving very few clues – even for family or friends – to spot.

"Because [snipers] kill from a distance, because the crime scene has little evidence and typically because the victims have no relationship to the shooter, there are very few clues for police," said Professor Alan Fox, an expert in criminal justice at Boston's Northeastern University.

"If this guy just stops there is a high probability that he will never be brought to justice," he told The New York Times. "It will be a good thing if he stops but it will be frustrating for law enforcement.

"The sniper is clearly getting his satisfaction. He did not kill these people for who they were. They were just targets of opportunity whom he killed to advance his dominance, power and control."