The Montgomery County youth soccer league canceled practice with an apologetic e-mail that noted "safety is paramount." Booths at the Connecticut Avenue pizza parlor sat empty, and sales are down 60 percent in a week. Shirts and sweaters hung unclaimed at the Kensington dry-cleaning shop whose promises of speedy service were rendered moot.

People "are afraid to come out, and I don't blame them," said Jane Pyon, owner of the Neet 'N Kleen dry cleaners, just a few hundred feet from where 25-year-old Lori Lewis Rivera was fatally shot at a Shell gas station Thursday morning.

Across the Washington region yesterday were signs that the news of yet another sniper attack -- this one at a Prince George's County middle school -- had forced many residents to concede that their initial outrage at the shootings had been transformed into a very personal fear.

The sniper, according to police forensic evidence, had struck in Montgomery, then the District, then Spotsylvania County and now Prince George's. No one knew where the attacker might strike next -- but it seemed as though he had surrounded the region. And that meant people confronted a choice: Should they change their daily routines in the name of safety? Or should they go on living as though nothing has changed? 

Shopping for groceries, sending children to school, filling up a gas tank -- the routine became notable, the ordinary fraught with exceptional precaution.

Lisa Cave, 35, a mother of three from Rockville, said she and her husband, Darrin, 36, have been open with their children about the shootings and have put new ground rules in place for their playtime.

"We say you can play in the back yard but not in the front," Lisa Cave said. "You can't ride bikes right now. You've got to be in before dark."

Heather Edwards, 24, and Tiffany Flakes, 22, both Howard University students, were shopping at Potomac Yard Center in Alexandria instead of their favorite store.

"We [usually] go to the Target store in Wheaton, but because of the shootings we decided to come here," Edwards said. "I probably won't be doing as much until they catch him. I won't go out to eat or go visit as much."

Nicole Burgess, 30, who works at the Bowie Wal-Mart, had a different reaction. Although her husband suggested that she stay away from the store, she refused. "I can't stay at home," Burgess said. "I have to go about my daily routine."

In fact, many people said that while they were acting carefully, they were continuing their chores and activities.

"I feel safe. I feel very removed from it," said Amy Kerr, 27, who lives near Capitol Hill. "I really don't think you can actually do anything about it.

The added fear also was reflected in the vigorous response to scary -- but ultimately false -- reports of new incidents.

At 16th and Holly streets NW, police were called to investigate reports that a man, armed with a rifle, was walking up and down 16th Street during rush hour. Police responded in force with dogs and horses but declared it to be a false report.

The Bowie Wal-Mart was the location of a prank when reports came to managers that there had been shooting in the parking lot. "It has been a tough day, an extremely tough day," said Bobby Marchbanks, the store manager, who spent much of the day reassuring customers that all was safe.

The shootings triggered increased patrols and activity among federal law enforcement agencies and D.C. police, including an e-mail advisory circulated to congressional staffers from Wilson "Bill" Livingood, the House sergeant-at-arms, urging them "to reduce outside activities to the extent possible."

District police increased patrols around schools, instituted routine checks with school administrators about suspicious incidents and intensified helicopter and harbor patrols, Officer Quintin Peterson said.

For many, the decision to take precaution was made for them. Managers at the Starbucks in Rockville removed all outdoor seating. School extracurricular activities, youth and adult recreation leagues and religious events were canceled yesterday.

At the Shoppers Food Warehouse at Georgia Avenue and Randolph Road in Wheaton, where the sniper's first victim, James D. Martin, 55, was fatally shot Wednesday evening, shoppers cautiously loaded their groceries into cars as two private security guards watched.

"We've certainly noticed more empty parking spaces here," said Iris Smith, 72, as she shopped for food with her husband, Don, 75.

"We're moving about our business of getting groceries and gas and things, but we're not going to stand around in the parking lot chatting," said Don, a church missionary.

Matt Luchsinger, 24, of Warrenton acknowledged that he was edgy as he put gas in his car at an Exxon station in Old Town Alexandria. "I've been looking at the tops of buildings and stuff," he said, but he added, "I'm not going to not leave the house because of some whack job."

Elaine Dodge, 45, a legal assistant who lives in Fairfax County and works in Alexandria, was standing outside the Giant store in Old Town and pondering whether it would be better to do her shopping after dark.

"I've kind of given a second thought to doing it later in the evenings," she said.

In some cases, people acted in a way that lent an almost morbid humor to the day.

"I had one guy get out of his car and duck between the pumps as he ran inside the station," said David Notestine, a mechanic at the Gasoline & Auto Services on Connecticut Avenue in Kensington, where sales have dropped 25 percent since one person was shot nearby.

When he got inside, Notestine added, the customer said, "Gee, I made it."

Staff writers David A. Farenthold, Michael Barbaro, Hamil R. Harris, Caryle Murphy, Elaine Rivera, Chris L. Jenkins, Eric M. Weiss, Lisa Rein, Fredrick Kunkle, Annie Gowen and Spencer S. Hsu contributed to this report.