Rockville, Md. ? Investigators hunting an increasingly brazen sniper defended their meager release of information, saying Sunday they don’t want the killer to know what they know.

Authorities pointed to the dangerous balance between pleading for public help and revealing too much.

“We don’t want to release anything that may cause … anyone to think they’re a suspect,” said Bureau of Alcohol, Tobacco and Firearms agent Mike Bouchard.

The sniper has been responding to police pronouncements: It seems the killer has adjusted his tactics in defiance of police statements and strategy a pattern of behavior that experts believe could help lead to his capture.

When police noted that the sniper strikes during rush hour, he picked off his next victim at 9:15 p.m. When police began discussing the “geographical profile” of the targets, the shooter left a 10-mile attack zone to shoot a woman in Virginia. And when officials insisted schools were safe, the sniper shot at a 13-year-old boy in front of his school.

These shifts in tactics suggest the killer is closely following the news coverage about him, and that introduces a third player: the news media. Police have relied on the news media since the shootings began Oct. 2 holding many briefings in the hope that the public will call in clues but they have also lashed out at journalists for reporting leaks.

Montgomery County police Chief Charles Moose, meanwhile, has cut back on his news briefings while saying he wishes there was more he could reveal.

“I wish we could give you a name, a mug shot and an address, but we’re not at that point,” he said in one of four appearances he made Sunday on national TV talk shows.

Tips pour in

The last killing the eighth, out of 10 victims occurred Friday morning, when a 53-year-old father of six was shot while fueling his sedan in a gas station just south of Fredericksburg, Va. At the time, a state trooper stood just 50 yards away, investigating a traffic accident.

Also Sunday, calls continued to flood tipster hot lines with information about white box trucks and a second white vehicle, a Chevrolet Astro van, seen at two or more of the killing sites.

And authorities began describing the serial sniper as not just a local threat, but an attempt to terrorize an already anxious nation.

“This reminds us that people in our past have tried to intimidate and put fear into Americans,” Moose said. “This a strong nation … and we will not be intimidated.”

Faith and fears

At the sprawling Covenant Life Church in Gaithersburg, Md., pastor C.J. Mahaney urged Sunday worshippers to turn off their televisions and turn to God.

“I am concerned there is too little faith and too much fear,” the preacher said from the pulpit.

Eighty-six-year-old Frances Pratt attended morning services at St. George’s Episcopal Church in Fredericksburg, a few miles north of the latest shooting.

“I don’t worry,” Pratt said. “Sooner or later he’ll be caught. They always are.”

At Landover, Md., police on horseback and bicycles ringed parking areas before Sunday’s Washington Redskins pro football game against the New Orleans Saints. Fans grilling burgers at tailgate parties said they welcomed the rifle-toting officers.

“I don’t think anybody in their right mind would try something out here,” said fan Bill Freitag, of Virginia Beach, Va. “But he’s not in his right mind to begin with.”

The victims, in Maryland, Virginia and Washington, D.C., were shot as they carried out daily errands, including mowing grass, shopping and pumping gas. Four were killed at service stations.

Official ‘no comments’

County, state and federal investigators won’t say if they know much about the killer, whose only apparent communication to police was a tarot card left at one shooting scene with the words, “Dear Policeman, I am God.”

Moose refused to comment on reports that the FBI has asked the Pentagon to search its records for recently discharged GIs who had gone through sniper school. FBI spokesman Mike Saltz declined to comment on any investigative leads and the ATF’s Bouchard said: “I don’t think you need special training. Obviously the person has practiced before.”

Investigators also would not discuss reports that a scrap of paper found at the site of the latest killing contained scribbled directions from northern Maryland to the Capital Beltway.