Jan Sweigert, 57, of Halfway, said her son is investigating the case as an agent with the Bureau of Alcohol, Tobacco and Firearms.
"It's very scary. I still go to malls, but it's still in the back of your mind," said Sweigert, who declined to give her son's name out of concern for his safety.
Ralls said his wife, Mary, works for the U.S. Commerce Department in Gaithersburg, Md.
Sue Penn, 63, of Beaver Creek, grew up in Washington and believes it's possible, although not likely, the sniper could strike here.
Mostly, the retired teacher said she worries about area children who are getting daily news updates. When her grandchildren visit, Penn said she turns off the television so they don't become alarmed.
Dick Ressler, 53, of Waynesboro, Pa., said he used to live in Montgomery County, Md. But as he was filling the tank of his orange pickup at a gas station near his house, he said he didn't give a thought to the sniper.
"Down there, there are so many different ways to get away, back ways to get from one point to another," he said.
Ernie and Nancy LeBlanc of Baton Rouge, La., who have been visiting family members in Greencastle, Pa., stopped at the same gas station Wednesday.
Ernie LeBlanc said he was mad at himself for not calling the police department's sniper hot line after he saw a white van with ladders on top matching a description police released.
"It wouldn't have hurt nothing to call it in," he said.
Most of the people who had stopped at the Martinsburg, W.Va., Sheetz off Interstate 81 early Wednesday evening said they are not worried.
"Why should I be nervous?" asked David Flemings of Martinsburg, as he filled his car's tank with gas. "I could die by anybody, going anyplace."
Flemings said he does not find himself looking over his shoulder any more now than before.
"Ever since the 11th, everyone's been looking over their shoulder," he said, referring to the Sept. 11, 2001, terrorist attacks.
Jerry Higbie, a member of the U.S. Air Force, sat wearing fatigues in the front seat of a car as another man pumped gas. He said he feels a bit vulnerable, "knowing that he could come up and shoot anytime."
Higbie said he finds himself noticing his surroundings, "making sure there aren't any white vans around."
Mark Dawson, who lives in Hagerstown and works in Martinsburg, agreed that he has not changed because of the shootings.
"Probably because of the proximity. I'm not close enough," he said. "I don't worry about a whole lot."
At the Wayne Heights Mall near Waynesboro, Pa., the sniper killings have not been a hot topic among a group of retirees who meets there daily, said Irvin McCleary, 81.
"It doesn't bother me because it's down there and I'm up here. Maybe I'm naive," he said.
Even so, McCleary said he isn't planning to visit the nation's capital any time soon.
"When you go the mall or something, you have to be afraid," said Marie Martin, 79, of Waynesboro, Pa.
Washington Township (Pa.) Supervisor Paul Benchoff, 77, said he worries more about copycat killers deciding to start a reign of terror in other large cities.
"Our whole country could be paralyzed by a half a dozen people," he said.
- Staff writer Candice Bosely contributed to this story.