W By Serge F. Kovaleski

ASHINGTON – The last three attacks linked to the elusive Washington area sniper were carried out near major highways that would have allowed the killer to come and go quickly, a marked shift from the seven previous stealth shooting incidents, which occurred closer to Washington D.C. in congested areas.

This apparent tactical change – similar to the one used by David Berkowitz, the serial killer known as “Son of Sam” who terrorized New York City in 1976 and 1977 – comes as law enforcement authorities have dramatically increased the size of their manhunt. A fatal shooting Wednesday night near Manassas, Va., was the seventh killing attributed to the sniper since the single-shot attacks began Oct. 2. Two people, including a 13-year-old boy, have been wounded. Another shot whistled through a Michaels craft store but hit no one.

More than 100 local, state and federal investigators flocked to the shooting scene just north of Manassas Wednesday night where a 53-year-old Gaithersburg, Md., man was killed at a gas station at Sudley Road and Balls Ford Road – a mere 940 feet from the closest ramp leading to Interstate 66.

Immediately after the shooting was reported to police, ramps to the interstate were closed, and two Virginia State Police cruisers watched the eastbound lanes, hoping to spot a suspect. But they waited in vain.

In Monday morning’s shooting in front of Benjamin Tasker Middle School in Bowie, Md., the 13-year-old boy was critically wounded by a bullet about 880 feet from the entrance to Route 50. And in a shooting Friday at the Spotsylvania Mall, a 43-year-old woman was wounded while loading packages into her minivan about 1,390 feet from the Route 3 ramp onto Interstate 95.

Bowie is about 12 miles east of Washington, and Manassas and Spotsylvania County, Va., respectively, are about 30 miles west and 50 miles south. By contrast, the previous seven shootings occurred in a congested urban area stretching about five miles north from Georgia Avenue and Kalmia Road in Northwest Washington to a shopping center near the Leisure World retirement community in Silver Spring, Md.

“The perpetrator appears to be much more organized than previously believed, in part because now the ante is higher, the hunt is more intense, and he has responded by coming up with more efficient escape routes,” said Richard Walter, a former prison psychologist who is head of the Omega Crime Assessment Group in Montrose, Pa., which does crime analysis and profiling.

“At this phase, he is concentrating more heavily on how to outfox the police after striking,” Walter said. “Previously, he was able to hit, blend and go away with less risk because people were still trying to put it together. He had more of an advantage then.”

During the initial spate of sniper attacks, beginning just before 5:30 p.m. Oct. 2 and ending 28 hours later, the assailant killed six people–five in crowded commercial areas of lower Montgomery County, Md., and one in Northwest Washington, a half-block from the Montgomery line.

From each of the locations where the attacks were carried out, there is no immediate access to a highway. There is usually heavy, stop-and-go traffic between all the shooting sites and the nearest highway, the Capital Beltway. The major roadways around the crime scenes include Rockville Pike, Connecticut Avenue and Georgia Avenue–all of which are lined with traffic lights and crosswalks.

The first two shootings, for instance, occurred during the Oct. 2 evening rush hour-at 5:20 p.m. near the intersection of Georgia and Connecticut avenues in Aspen Hill, Md., and at 6:04 p.m. near Georgia Avenue and Randolph Road in Wheaton, Md. In that time, the assailant may have been able to use the normally thick traffic on any of those thoroughfares as camouflage.

The major road near the third shooting, at 7:41 a.m. Oct. 3, is Rockville Pike, where rush-hour traffic moves slowly toward the Beltway and Interstate 270.

Joseph Borrelli, a retired New York City chief of detectives who was one of the lead investigators in the Son of Sam case, said there are similarities between how Berkowitz chose his attack locations and the way the Washington area sniper has been operating.

“In the beginning, his attacks were mostly on side streets, and later on, they moved to areas that were closer to major arteries,” Borrelli said of Berkowitz, who was arrested in August 1977 after a parking ticket led authorities to his Yonkers apartment building.

The shift in locations led detectives to believe that Berkowitz was traveling by car rather than by public transportation or on foot. “That’s why we started looking at traffic summonses in the general area of the attacks,” Borrelli said.

There may also be a parallel between the sniper’s more recent movements and Berkowitz’s decision to strike in Brooklyn while a task force of investigators was focusing on his earlier shootings in Queens and the Bronx. “He assumed we were concentrating on certain things, and he was right,” Borrelli said.

As for the sniper, he struck in Spotsylvania on Friday after the police presence was significantly beefed up in Montgomery. Then he shot the boy in Bowie, in Prince George’s County, on Monday morning before heading southwest and killing the man fueling his car near Manassas on Wednesday night.

All the victims were going about ordinary tasks – pumping gas, mowing grass, walking into a school – and none was moving fast.

“He is acquiring stationary targets who he knows will be standing there for multiple seconds to several minutes,” said former FBI profiler Clinton Van Zandt. “He does not appear to going after certain groups. He is simply looking for a target that is representative of the community – in essence, another human being, regardless of any demographics.”

Van Zandt said he believes that the sniper wants to make sure that authorities know he is the one committing the killings by using the same .223-caliber weapon and the same method of operation: “one shot, one victim.”

He also said there may be a practical reason for shooting just once in each attack–because as sound bounces off walls and other structures, it is difficult for people to determine from what direction the shot was fired.

“A second sound could help you locate it,” Van Zandt said. “I think he is careful not to draw attention to himself.”