On the eve of another weekend of postponed homecoming games, of protective postures at the gas pump, of barren public spaces, Steve Coleman had a question: Is the Washington region's collective response to the recent sniper killings -- a reaction that experts say is without precedent -- appropriate? 

Coleman, director of the nonprofit Washington Parks & People, reluctantly joined the list of those who canceled weekend events, his being a public movie screening at a park in Northeast Washington. He didn't want to, he said, but the city told him to do it.

"I don't understand it," he said. "We didn't shut down after Sept. 11, and we've had hundreds of people killed every year in Washington by gunfire. I think administrators at schools are worried about liability, and the school lockdowns seem to be fueling the other decisions being made across the board."

Even if few are going so far as to baldly suggest that the region is overreacting, Coleman isn't alone in questioning the continuing public response 2 1/2 weeks after the sniper began terrorizing the region. But those questions don't lend themselves to easy answers, say experts who study the effects of serial killings on communities. That's because this case -- and the subsequent public response -- are without precedent in recent U.S. history, they say.

"The Boston Strangler, the Hillside Strangler, the Atlanta child murders, the Zodiac Killer, the coed murders at the University of Florida -- none of them were like this," said James A. Fox, a professor of criminology at Northeastern University in Boston, who has studied serial killings for 25 years. "The risk here is not restricted by any demographic characteristic, so everyone feels like a target. In Gainesville [at the University of Florida], for example, the victims were middle-class coeds, so it didn't have the broad impact. They didn't cancel football games there, because [the targets] wouldn't have fit the pattern. Here there is no pattern."

And when anyone might be a target, taking cover is natural.

"The normal reaction is to cower and hide, and people who don't have that reaction initially probably have more reason to question their response than those who do," said Barry Glassner, a professor of sociology at the University of Southern California and the author of the book "The Culture of Fear." "But that's just the initial reaction. At some point, the question becomes, 'Where do we go from here?' " 

The answer, he said, generally comes from leaders of area schools and local governments. Since the first sniper shooting Oct. 2, a sort of domino effect has spurred decision-makers: School systems have decided, in conference calls with law enforcement arranged through the Metropolitan Washington Council of Governments, to suspend all outdoor activities. Then day-care centers and youth soccer leagues have followed the lead of their public school systems, and smaller community groups have fallen into line.

An example: When the Montgomery County school system announced that it would cancel all outdoor events this weekend, the city of Rockville consequently postponed an auto show, its weekly farmers' market and all recreation activities that take place outside. Rockville's historical society, in turn, canceled its annual house tour and antiques and crafts fair. Then organizers of an arts festival in Bethesda decided to pull the plug, too.

And now, another domino is falling as others question the messages, intended or not, that the mass cancellations send.

"You have a . . . situation where nobody wants to be the first to stand up and give the message, 'We're not going to allow you to intimidate us,' " said William O. Ritchie, a retired D.C. police deputy chief, who said his opinions don't necessarily reflect those of a security firm he now works for. Ritchie added, "The community as a whole is going to have to step up to the plate, along with some support from law enforcement, and go on with the rest of their lives."

With a killer at large and the most recent slaying only days old, it could take a while before a suitable comfort level returns, Glassner said.

In past cases in which a serial killer has terrorized a community, victims could generally be grouped into specific categories that excluded the majority of a community's residents. David Berkowitz, the "Son of Sam" killer in New York in the 1970s, targeted dark-haired women and their escorts. Ted Bundy targeted female students. Wayne Williams targeted black children in the Atlanta area.

"The unknown is what people fear most," said Louis Graham, chief deputy of the DeKalb County (Ga.) sheriff's department, who investigated the Atlanta child murders. "In our case, the governments were encouraging everyone to continue life in a normal way, and it was the individual families who were the ones who made changes. They stayed close to their kids and tried to protect them."

Most serial killings in recent history also have progressed much more slowly than have the sniper shootings, in which 12 incidents -- nine of them fatal -- were reported in less than two weeks. The six murders committed by Berkowitz, conversely, stretched over 13 months. The more than two dozen Atlanta child murders attributed to Williams stretched over several years. The Boston Strangler killed 13 people in 18 months from 1962 to 1964.

The Zodiac Killer was the name given to a person who wrote to San Francisco newspapers in the late 1960s and early 1970s claiming to have killed more than 35 people. Although that case prompted intense public concern -- police accompanied school buses in three counties around the Bay Area after a newspaper received threats of shootings and bombings on school buses -- the public's exposure to the case wasn't nearly as widespread as in this one.

"Another difference is the media today," said Fox, who remembers when the Boston Strangler grabbed headlines in the days before 24-hour news coverage. "The Boston Strangler didn't attract the pervasive media attention. That's not going to calm fear. It's going to accentuate it."

A community can calm its fears, Glassner said, by feeling that its residents have some control over their situation. That hasn't happened yet, he said, but it could as a little more time passes.

"It's only when public opinion changes with regard to whether children should be in school that I would expect decision-makers to do something other than continuing a lockdown," Glassner said.

This weekend, some schools are taking tentative first steps to resume outdoor activities. Montgomery County public schools, for example, plan a meeting Monday to discuss "ways in which some, if not all, of the outdoor sports can be resumed, with considerations being given to the availability of time and locations for sufficient practice sessions, as well as security, facilities, transportation, equipment and other factors."

Some impatience with all the caution could be witnessed heading into the third weekend of sniper anxiety. In today's Washington Post, a parent of a student at Sidwell Friends School took out an advertisement in the Sports section that states, "Sorry, Sidwell Friends' homecoming is cancelled due to paranoia and bad judgment." The school, along with the visiting opponents, chose to cancel games scheduled for the weekend because of the sniper,though the homecoming dance will still be held.

Several other events -- such as the Clarendon Days neighborhood celebration in Arlington -- will take place today as scheduled.

"We felt like the community needed a place to bond and react, to feel out their emotions with other people," said Sona Virdi, executive director of the Clarendon Alliance, the community group organizing the event. "We'll all be cautious, but we didn't want to cancel."

Coleman said that's the right approach.

"The way you make streets safe is by occupying them," he said, "not by abandoning them."

Staff writer Debbi Wilgoren contributed to this report.