PCP, a drug known for its unpredictable and often violent high, has surged in popularity after spending years on the margins of Washington's narcotics culture, according to police and health workers.

The drug is most often ingested by smoking "dippers," cigarettes soaked in a PCP solution, and its resurgence has been charted in emergency rooms, detox clinics and, most prominently, several bizarre homicides from the District to Charles County. Adopted by a new generation, PCP's sudden return has surprised authorities who saw it nearly erased by crack cocaine.

"A lot of adults, they don't know about the dipper. But the kids know," said Theophus A. Brooks, who works with D.C. public school students on the Youth Gang Task Force. "You smoke it, and sometimes you're all right. And sometimes you smoke it, and your mind snaps."

PCP, whose full name is phencyclidine, was developed in the 1950s as an anesthetic and is snorted, smoked and eaten. It was popular in the Washington area in the 1970s and 1980s, usually sprayed on cigarettes stuffed with tobacco, marijuana or parsley. The drug was then called "Sherm," "the Love Boat" or "Buck Naked" because so many of its users shed their clothes while high.

But when crack cocaine took over inner-city markets, PCP became a "redneck drug," according to Thomas H. Carr, director of the Washington-Baltimore High Intensity Drug Trafficking Area, a federal program that aids law enforcement and drug treatment. In this region, PCP held on mainly in poor neighborhoods in areas such as Dundalk, in Baltimore County, and the Yorkshire area of Prince William County.

Then, in 2001, a new form of PCP more convenient for users and dealers began appearing in force in Prince George's County and Northeast and Southeast Washington.

Now, dealers holding small vials of yellowish liquid let customers dip cigarettes in PCP for $5 to $25 apiece. Smoking dippers gives four to six hours of an unpredictable, often violent high.

Use of the drug still lags behind use of marijuana and cocaine, but any number of statistics can mark the increase in PCP use. Detoxification patients in the District now test positive for PCP six times more often than in 1999. The Prince George's County police laboratory, which tests all drugs seized in the county, received more than 115 PCP samples in 2002 -- up from eight in 2000. D.C. police estimate that they saw the drug four times as often in 2002 as in 2001.

"It was a pretty phenomenal change," said Christopher Wuerker, an emergency room physician at Washington Hospital Center. "It seemed to go from a drug that was out there and you'd see it occasionally, to seeing it constantly."

Inspector Hilton Burton of the D.C. police Major Narcotics section said that someone may have set up a PCP lab in the D.C. area but that, if so, authorities do not know its location. The biggest manufacturers of the drug have always been Los Angeles street gangs, who ship their product to the East Coast, Burton said.

For dealers, there are enormous profit margins: A one-ounce vial costs $300 to $450, and selling the drug by the dip can yield twice that. Authorities in Baltimore raided a home in November and found more than 30 gallons of PCP and ingredients to manufacture more -- a potential street value of $50 million to $100 million. Authorities think another PCP lab may be operating.

One night before Christmas, undercover officers from the D.C. police Narcotics Strike Force approached a dealer in the 1200 block of 18th Street NE, a wretched dead-end strip east of Trinidad where two suspected PCP customers were killed last year. "Gimme two dips," the officer said, and the dealer retrieved a small vial from a hiding place alongside concrete steps.

Police swarmed the area a few minutes later and found two vials of the drug -- one with tiny bits of tobacco still swirling in the bottom. "That's PCP," said Sgt. Wilfredo Manlapaz. Most likely, police say, it was powdered PCP mixed with ether. Searching the nearby weeds with flashlights, officers found a loaded 9mm pistol hidden inside a foam carryout container.

Some of last year's most startling homicides have involved the use of PCP. In October, police say, 18-year-old William Sanders shot and killed Melvin R. Douglas, 42, a man he considered his stepfather. A detective said Sanders, who had been smoking PCP for several days, "got this thing in his mind that [Douglas] had killed his real father 20 years ago."

Sanders allegedly shot Douglas several times in the head, then stuffed his body in the back of Douglas's taxicab and drove to the Reliable Cab Association garage at 45 Q St. NW. There, the detective said, Sanders asked for help disposing of a body. A cab association employee called police.

On Oct. 24, 2001, Jeffery E. Allen, a homeless man from the District, smoked three dippers before getting into a car with four other men who took him to Charles County, according to testimony from his trial in August. Allen testified that he got the dippers from friends on Fifth Street NW.

The next morning, Allen stabbed to death one of the Charles County men; he was convicted in August of first-degree felony murder.

The drug has been tied to other mayhem. A woman believed to be high on PCP approached D.C. police officer Mark McConnell in the 400 block of Seventh Street SE on Dec. 13 and asked him for directions to College Park. As McConnell started to answer, she put a pistol to his head and fired. McConnell ducked in time to avoid injury, police said, but the shot was so close he had gunpowder on his face.

At least twice in recent months, D.C. medical workers have had to stop their ambulance and bail out because they were treating an unruly PCP user, said Kenneth Lyons, who heads the city's medic union.

Some of those hurt the most have been teenagers. Bridget T. Miller, another member of the D.C. schools Youth Gang Task Force, said she has known students who have almost killed themselves with overdoses of PCP, and one student who pulled out a gun and shot himself the first time he smoked a dipper.

Miller said she has a simpler view of the brutal drug's new popularity: Its horror stories are its best advertisement.

"It's crazy," she said. "But a lot of them, if . . . they see a drug out there and it has effects like that, they're dying to buy it."

Staff writers Michael Amon, Jamie Stockwell and Josh White contributed to this report.