District of Columbia Mayor Marion Barry insisted that the record number of killings in the nation's capital pose no threat to tourists, saying most murders involve drug dealers and users targeting each other.

But in neighboring Alexandria, Va., officials shaken by the shooting death of a police officer by a suspected drug dealer questioned whether Washington's drug-related violence is spilling over to neighboring areas.Cpl. Charles Hill, 40, a 13 1/2-year veteran of the Alexandria police force, became the first officer in the city since 1972 to die in the line of duty. He was shot in the head Wednesday night by a suspected drug dealer wielding a shotgun.

Following the shooting, Alexandria Mayor James Moran said he had thought Alexandria was immune from such violence.

"You do the best you can," he told WUSA-TV Thursday. "You provide the resources that you need to stay on top of the problem and you just hope that the kind of violence that has occurred across the river doesn't come here."

The district had a record 372 killings in 1988, giving it the nation's highest per-capita murder rate. So far this year, 120 people have been killed, most in drug-related violence.

Mayor Barry, trying to restore the tarnished image of the nation's capital before an estimated 1 million people arrive to view the city's famed cherry blossoms, said Thursday that Washington is safe for residents, tourists and businesses.

"For the most part, the targeted killings and drug activities take place in the small sector of our city," Barry said at a National Press Club luncheon. "Over the last three years, research shows that 80 percent of murder victims know their assailants," he said. "And, that 60 percent of the deaths are from shootings."

Barry also said 85 percent of he city's murder victims either have drugs in their system or drug paraphernalia is found nearby.

A Washington Post poll Thursday said that half of all Americans consider the nation's capital the most murderous and corrupt big city in the land.