FAIRFAX, Va. - Police said on Tuesday new evidence gleaned from the ninth murder by a sniper in the Washington area gave them the best chance yet of catching the serial killer whose latest victim was shot dead while loading her car with shopping bags.

FBI employee Linda Franklin, 47, was killed in front of her husband by a single shot to the head late on Monday in the parking lot of a Home Depot hardware store in Falls Church, Virginia.

"There was some additional information we were able to get from last night's case and I am confident that ultimately that information is going to lead to an arrest in this case," Fairfax County, Virginia, Police Chief Thomas Manger told a news briefing.

Charles Moose, the police chief of Montgomery County in neighboring Maryland, said Franklin, an FBI intelligence analyst, was not involved in the sniper investigation and was therefore considered yet another random victim.

For the 11th time in less than two weeks, the gunman eluded authorities in spite of the quick deployment of dozens of federal, state and local law enforcement agents who shut down major arteries around the scene and searched vehicles.

The sniper's random attacks have spread fear in a wide area around Washington since a 15-hour killing spree was launched on Oct. 2 and Oct. 3 that quickly claimed five victims in the suburban neighborhoods northwest of the U.S. capital.

Another victim was killed in Washington proper and two others in the city's southern suburbs in Virginia.

The sniper has also wounded two people: a 13-year-old schoolboy in Bowie, Maryland, northeast of Washington, and a woman in Fredericksburg, Virginia, to the south.

SPREADING FEAR AND ALARM

As the toll has mounted, fear and alarm have spread across the area with schools keeping students indoors, football games canceled and residents thinking twice before making routine trips to shopping malls or gasoline stations.

Police said they were not yet ready to give out information from witnesses on the license plate of the vehicle, which could either be a light-colored Chevrolet Astro van or a Ford Econoline van, believed to be the gunman's getaway vehicle.

Local media have variously reported that the van leaving the busy suburban shopping center about seven miles west of Washington after Monday's killing had Maryland or Virginia plates.

Police said the van has a silver ladder rack on the top, a detail consistent with the description of the vehicle sought after Friday's shooting death of a man in Virginia, and a malfunctioning left tail light.

Police released composite pictures of two white vans similar to the ones being sought, but they have so far held back from releasing a composite of the killer.

Police could not confirm local news reports that some witnesses had seen the killer get out of the van to fire and then get back in.

The sniper, who uses a high-velocity rifle to pick off random victims, has so far eluded a massive hunt by law enforcement agencies, including the FBI, with some help from the CIA.

SOLDIERS TO SUPPORT SEARCH?

Defense officials said Defense Secretary Donald Rumsfeld was carefully considering whether to let troops take a supporting role in the search for the sniper, such as perhaps operating surveillance equipment.

But troops, if they became involved, would take no active part in the police search as this would be illegal.

An FBI spokesman declined to discuss any specific investigative steps being taken, but said any help from the military would be along the lines of checking or searching military records and databases for individuals with certain training, for example.

FBI Director Robert Mueller said the agency had 400 agents working on the case, including teams of new agents in training who were working a toll-free hotline.

The CIA, at the request of law enforcement agencies, has been supplying bomb-sniffing dogs, a spokesman said. The dogs can sniff out ammunition and explosives in the sniper hunt. As in the most recent attack at a gasoline station in Spotsylvania County, Virginia, on Friday, authorities responded quickly on Monday, closing major traffic arteries for hours as police converged on the 500,000-square-foot mall.

Helicopters shone high-intensity lights over woods and neighborhoods in the area, which is a mixture of strip shopping centers, single family homes and apartment buildings.

But Manger said there were so many ways to leave the suburban center and it was difficult for police to find the gunman.

Physical evidence in the cases has also been scant, with one taunting clue apparently left by the methodical shooter near where the young boy was shot: A Tarot "Death" card with "Dear Policeman, I am God" scrawled on the back.

A $500,000 reward is offered for information leading to the sniper's capture.