The sounds of sirens and helicopters awakened Leonard Buck in his Aspen Hill home yesterday morning, and as he rolled out of bed, one thought filled his mind: "Another dead."

Because the commotion outside was so great, Buck said, he knew that the sniper who has been terrorizing the Washington suburbs and beyond since Oct. 2 had probably struck again, right in the community where the series of attacks began. And with the latest fatal shooting, of a Ride On bus driver stopped in the area, Buck and many of his neighbors are now convinced that they know at least one clue to the sniper's identity.

"I think he lives around here," said Buck, 63, owner of an air-conditioning and refrigeration company, as news and police helicopters droned overhead, hours after the shooting.

Across the metropolitan region, and as far south as Richmond, the news that a 10th killing may be linked to the sniper drew emotions ranging from heightened fear to anger to weariness with the continuing siege of violence. Three other shooting victims have been left injured in the random attacks that have altered the course of everyday life in the area and forced people to look over their shoulders as they shop, wait for a bus or simply walk down the street.

"It's scarier than ever," said Chante Turner, a 23-year-old waitress, as she hurried up Georgia Avenue to the Manor Apartments, adjacent to the latest shooting scene, after a quick trip to a nearby convenience store. "I have to ask my husband if I can go to the 7-Eleven."

Turner figured it was about the safest time possible to leave home for a minute, what with police cars and investigators crowding the area, and her brother, Andrew Springs, 16, acting as bodyguard. But as the days pass, the victim count mounts and investigators continue to appear baffled, her window of "safe time" is shrinking.

"I really don't think they're going to catch him for a while, and he knows what he's doing," she said. "So I'll be staying in the house."

It has been three weeks since the shooter surfaced and the Washington area's usual rhythms of life were disrupted -- and the strain seems to be wearing on everyone. Area schoolchildren, who have been denied outdoor activities for most of the month, are restless and fretful. Adults are weary of going to bed or waking up to the news of the latest attack.

With the police dragnets instituted after each of the last few shootings, many area residents now feel they are less likely of getting shot by the elusive sniper than of getting trapped in a massive, hours-long traffic jam. Local news outlets have been offering tips on how to endure interminable waits in the car, advising a cache of food and water -- and a reduction in coffee-drinking to lessen the need for a pit stop.

Local news outlets have been offering tips on how to endure interminable waits in the car, advising a cache of food and water -- and a reduction in coffee-drinking to lessen the need for a pit stop.

In the neighborhood where it all began Oct. 2 with a series of shootings that first shattered a window at a Michaels craft store and continued the next day until five victims were dead, the news of the possible return of the killer was chilling, but not much of a surprise. The area is filled with high-rise apartment complexes, condominiums and single-family homes, and residents believe only someone familiar with the local traffic patterns could so easily negotiate an escape through the maze. By contrast, the forays into Virginia have been just off the interstate.

"He goes to Virginia, and everybody calms down and gets a false sense of security," said Jeff Taggart, 46, an engineer at the Wintergreen Plaza shopping center in Rockville. "Then he comes back and starts the terror all over again. He feeds on people being afraid."

Dick Hottel, a heating and air-conditioning company owner who lives in Rockville, not far from Aspen Hill, agreed that the sniper "lives in our back yard" and had a suggestion for police.

"I think they should search all the damn cars in the area and all those apartments over there," he said. "I don't think anyone would complain if they did, and if they do complain, what does that tell you?"

Walter Patterson, 63, who lives at the Ridgeview Apartments near the latest shooting scene, would not protest such a search. He is ready for the sniper to be caught, but he does not think that will happen without "a lucky break or a mistake." He, too, is certain the shooter is a neighbor.

"He is bold enough to shoot not just during rush hour but in a variety of places in the same neighborhood," Patterson said. "This has to be a person who knows the flow of traffic and which are the best roads to go down. Whoever he is, he is just really coldblooded. . . . I don't know what the police can do except keep trying."

For Debra Johnson, who works at the post office across the street from yesterday's shooting, the possible return of the sniper revived the unwelcome thought that she or a co-worker could become a target. Johnson, who began her shift at 3 a.m., stepped out to get coffee yesterday morning, only to see police cars descending on the scene, sirens blaring.

"It felt scary, because it could have been one of us," she said.

But a few residents vowed not to be cowed, no matter how close or how frequent the attacks. Mary Rugur, 78, a resident at nearby Leisure World, had just finished lunching with a friend at an Italian restaurant at the complex's shopping center. And she will do it again if she feels like it, she said.

"It's not going to stop me from going out," she said. "I'm not going to let them deter me."

Residents of the Northgate Apartments on Grand Pre Road in Montgomery County watch police activity.