Loudoun County and Virginia law enforcement officials say two young Northern Virginians found murdered on a back road within sight of Dulles International Airport earlier this month were executed in what they believe may have been a drug-related ambush.

They described the double slaying as one of the must brutal in recent history in the fast-growing count of Washington's outer suburban ring.

"The nature of the evidence indicates it was just a brutal, cold-blooded murder," said Loudoun prosecutor Thomas D. Horne.

Horne said county investigators had been planning a crackdown on a major illicit drug network believed to be operating in Loudoun horse country when the couple was killed.

One of the victims, 20-year-old Tommy Meadows of Arcola, was among those being investigated, Horne said. "We were just about to do something when it happened."

County Sheriff Donald Lacy said several alleged drug dealers have been identified as possible suspects in the slayings, although no charges have been filed.

Meadows and his 20-year-old girlfriend, Patricia Mae Fisher of Aldie, were shot to death nearly three weeks ago on a narrow, dark road between Leesburg and Sterling.

Officials have refused to release most details of the slayings, but sources close to the investigation theorize that Meadow and Fisher were involved in a high-speed chase down the county's winding back roads shortly before they were killed.

Shots were fired through a side and a rear window of Meadows' customized four wheel drive pickup truck. Meadows may already have been wounded, sources said, when he drove his truck off Rte. 659 through a barbed wire fence near a Fairfax County water treatment plant. The bullet-riddled truck then swerved back across the road, coming to rest in brambles and bushes off the shoulder.

"Whoever did it had to be a darned good shot," prosecutor Horne said.

Horne refused to divulge results of autopsy and ballistic tests completed this week. Sources indicated, however, that both Meadows and Fisher were struck by bullets fired through the truck's rear window, then shot "execution-style" in the head at close range.

"The inside of the truck was covered with blood," Horne said.

State police, involved in the investigation along with Sheriff's Department officers, say they are following numerous leads. Several persons have taken lie detector tests, according to the state police special agent Robert C. Martin.

Among those questioned, Martin said, were several persons involved in a July 27 melee in Sterling Park that resulted in assault charges being filed against Meadows.

Meadows was accused of trying to drive over three persons with his truck on a front lawn. All three assault charges were subsequently dismissed.

According to Horne, another possible suspect in the slayings was a county sheriff's department officer, whom Horne declined to name.

But Agent Martin said Wednesday there is "not a shred of evidence" implicating a county officer. Sheriff Lacy also denied that anyone in his department is a suspect.

Friends and relatives of Meadows say they knew, or suspected, that the youthful truck driver was selling drugs before he was killed. But they doubt drugs played a role in his murder.

"A lot of people do that around here," said one friend, John Weller, 23, of Ashburn. "But he wasn't into anything heavy enough to get blown away over."

Of great mystery to friends is how Meadows arrived at the isolated back country crossroads where his truck was found Nov. 8.

About an hour before a passing motorist spotted Meadows' disabled truck, Meadows and Fisher had joined Weller and another friend in the Sterling Park Shopping Plaza parking lot, a favorite meeting place.

Shortly before 9 p.m., Weller recalls, Meadows left saying he "had to see someone" and would return in about 15 minutes.

Weller and his companion waited about a half-hour, then left, Weller said.

The spot where Meadows' truck was found about 10 p.m. is several miles west of Sterling Park.

"Whoever did it must have stopped him," Weller said, '"cause that boy sure could drive that truck."