MANASSAS, Va. -- Margaret Meyer gassed up her blue-and-gray Ford van at a Sunoco station here just two hours before a fellow customer was shot and killed at pump No. 4 on Oct. 9.

She returned for the first time Wednesday night.

"I'm not going to live in fear and let some creep dement my world," Meyer said as she waited inside the station with her 20-year-old son while her van filled automatically.

She then took two deep breaths and ran to the car as her son trotted alongside, providing a protective shield.

After nine fatal sniper attacks across the vast stretch of suburbia surrounding the nation's capital, many residents are responding with a cautious defiance similar to that which swept the nation in the aftermath of the Sept. 11 terrorist attacks.

Thousands have altered their daily routine -- some drastically -- but at the same they insist that the elusive sniper will not deter them from living their lives.

"It's absolutely insane with all this happening," said Christy Tull, an assistant manager at an apartment complex in Fairfax, Va.

"But you have to get out there and get on with life."

Even those who occupy Washington's institutions of power feel vulnerable.

No more trips to mall

Sen. Kay Bailey Hutchison, a Texas Republican and the mother of two toddlers, said she was gripped by thoughts of danger while walking with a friend on the National Mall.

"I was thinking to myself, 'What are we doing here?'" she recalled.

"You think about it all the time because this horrible person is undetectable. So anyone could be a sitting duck."

The sniper's impact on daily routines has been sweeping. Schoolchildren spend their days indoors. Online shopping services are overwhelmed by customers reluctant to venture out. Athletic schedules at many suburban high schools have been ripped up.

Motorists begin to plot as their gas needle moves toward empty.

Many go to full-service stations.

Others bob and weave as they fill up at the tank -- or as they walk through the neighborhood.

The attacks also have rearranged the capital's comfort zones. The city's tough inner city has been spared thus far, while wooded, affluent suburbs have borne the brunt of the sniper's crime wave.

In Anacostia, the city neighborhood with the highest crime and dropout rates, two office furniture movers stood unconcerned in the parking lot of the Anacostia Warehouse Supermarket.

"You see death happening here every day outside the sniper, that's why I'm not afraid," said Kevin Smith, 31. "You're not going to change what you do everyday because you've got some fool that's hiding and shooting at you from long range. You've got fools high off PCP right here that will walk up to you and shoot you."

"That's everyday living right here in Southeast Washington," added co-worker Tim Eady, 33.

Until recently, Meg Kaplan, a 27-year-old clerk at the federal courthouse in downtown D.C., routinely woke up at 5 a.m. to run around her Alexandria, Va., neighborhood, as a part of a marathon training program.

Now, she runs at lunchtime through the crowded streets near the U.S. Capitol because, "I feel safer."

Psychiatrists and sociologists agree that the spate of killings is further taxing a region hit by both the Sept. 11 terrorist attack on the Pentagon and anthrax attacks last year. They differ on the extent of the damage, however.

"Everyone has a higher sense of anxiety, but I don't think that most people are panicking," said Dr. Rosemary Schwartzbard, a specialist on the effects disasters cause on mental health.

"They are being more cautious, but they are not totally preoccupied with it."

Dr. Dorree Lynn, a Washington psychologist, believes that the string of sniper attacks has had an even more profound effect than 9-11.

While the Sept. 11 attacks galvanized the nation with a patriotic fervor, she said, the sniper assaults are chasing people into their homes.

"It's isolating people instead of bringing people together," she said.

Michael Losow, a 44-year of father of two, perhaps typifies the suburban routine in the aftermath of the sniper attacks.

He and his family live in Kensington, Md., in a neighborhood his wife, Marcia, once likened to TV's fictional small-town, Mayberry, RFD.

Now, he says, it's more like a scene out of "Buffy the Vampire Slayer."

He or his wife joins the procession of neighborhood parents who now take their children to school and escort them home.

He deposited family checks in a D.C. bank so his wife wouldn't have to risk waiting in line at a suburban bank.

His son walks the neighbor's dog in their backyard instead of on the street.

Like virtually every parent in the Washington area, the Losows have a bottomless fear of what the sniper might do on Halloween.