The FBI investigation of alleged corruption among some D.C. narcotics officers represents a dubious coming of age for a department that has been known for decades as relatively free of taint.

Current and former D.C. police officials, as well as law enforcement experts throughout the country, say that it was only a matter of time before the District would become caught up in the same net that has led to corruption in dozens of law enforcement agencies nationwide: drugs.

D.C. Police Chief Maurice T. Turner Jr. has said that the explosive growth in the sale and use of drugs here in the last two decades has made it the department's top priority. Nearly one-fourth of the District's 3,880 officers are involved somehow in narcotics enforcement.

Police experts provide a simple formula: The more drugs, the more potential for police corruption.

"With the increase in drugs, you're talking about an amount of money most policemen don't normally see in 10 years, and a greater opportunity and temptation," said Robert W. Klotz, a retired deputy D.C. police chief who is a consultant on law enforcement corruption.

The allegations under investigation in the District -- that detectives kept drugs and money seized in raids, leaked information about a big raid to dealers and generally became too cozy with some alleged dealers -- closely resemble the facts outlined in several prosecutions of rogue narcotics squads around the nation, from New York to Chicago to Miami.

Indeed, the consensus among law enforcement officials is that narcotics work is the most corruptible of all because of the huge amounts of money involved, the relative discretion with which vice investigators work and the close relationships they often have with their drug informants. Another lesson, they say, is that improprieties in narcotics units seem to flourish in an atmosphere of loose supervision.

"It's a slippery slope," said Patrick Murphy, who was D.C.'s public safety chief in 1967 and 1968. "In many respects, management is the issue. All over the country right now, there are sergeants, lieutenants and agents sending narcotics squads out on the street and saying a little prayer.

"It's a risky business," said Murphy, who is considered one of law enforcement's leading fighters of corruption for his work as New York City police chief in the 1970s.

"You're talking about a . . . minefield. Being a vice officer is like being in Vietnam, " said Isaac Fulwood Jr., the D.C. police department's second-in-command as assistant chief for field operations. "It is one of the most stressful assignments you can have . . . . You can't imagine the {informant} cutthroats out there that you need in a complex narcotics investigation."

In the midst of the local probe, top D.C. police officials are reviewing aspects of the department's narcotics enforcement: its management, organizational structure and selection and training of vice officers and commanders.

"We've got some systems that are faulty and need refining," Fulwood said. "Management has to develop a system to supervise {narcotics officers}, to give them clear directions and also to maintain the physical and mental health of the people that are assigned to vice."

Some current and former local law enforcement officials said that supervision of D.C. vice officers sometimes is less than strict.

"My sense is in vice work, the individual police officer is given a lot more leeway than in any other area," said W. Randolph Teslik, who until last year was head of the grand jury section of the U.S. attorney's office and had extensive dealings with D.C. police.

Because narcotics work depends on an officer's initiative, many detectives generally are supervised only by their sergeants, if at all, Teslik said, adding that some officers do not provide the identities of their informants even to superiors. While detectives in robbery, for instance, keep written records of investigations in progress, narcotics officers rarely do, Teslik said.

"The nature of the work is that a lot of it is independent," Fulwood said. "I don't know that even with all the best guidelines in the world it would be foolproof."

James P. Shugart, a retired D.C. deputy chief who until June commanded the 4th District, the main target of the FBI probe, agreed.

"An officer assigned to vice walks a very thin line between being a police officer and being part of the criminal element, and I think we put him in jeopardy by giving him that assignment," Shugart said at a recent news conference. Choosing between good police work or corruption "is up to the individual investigator," he said.

Without commenting on the specifics of the D.C. case, 12 police officials and law enforcement specialists interviewed for this story said the 4th District allegations sound strikingly like those raised in numerous other jurisdictions. The experts say narcotics officers' vulnerability to corruption often stems from the special "police culture" of vice squads.

They say that corruption is often spawned by the especially virulent frustration shared by narcotics officers. It seems that no matter how hard the vice officers work, the drug problem continues. They give as an example the D.C. police's drug crackdown, Operation Clean Sweep, which has resulted in more than 12,700 drug-related arrests for various drug offenses in one year.

"The feeling is, 'We're fighting this thing that never goes away,' " said Jim Fyfe, a law enforcement studies professor at American University and a former New York City police officer. "It creates a tremendous amount of cynicism" watching drug pushers go back to the streets soon after the officer finishes the paper work, Fyfe said. "You feel like you're hitting your head against a wall."

The frustration of being a police officer in a world awash in drugs was obvious in the case of Brian O'Regan, a New York City officer in a poor Brooklyn neighborhood. One of 11 plainclothes officers in his precinct charged with such crimes as burglarizing pushers' apartments and selling drugs to dealers, O'Regan admitted his crimes last year to a New York magazine reporter, and explained why he did what he did.

"It was you finally getting back at all the slaps you took," O'Regan said. "It was getting back at {the criminals}, back at people you couldn't hit . . . . It's funny how you can be good for your whole life, for so long, and then . . . . " A few days after the interview, on the morning he was supposed to turn himself in to authorities to face 82 criminal counts, O'Regan shot and killed himself in a motel room.

The tale of O'Regan and his colleagues illustrates how officers' dilemmas can deepen as they become familiar with drug dealers and users, said police experts. So-called victimless crimes such as narcotics, prostitution and gambling by their nature require officers to mix frequently with criminals because it often is the only way to obtain information. Most other police work -- such as investigating hit-and-run accidents or rapes -- places officers more frequently in contact with the victims.

Narcotics investigators often get informants by pressuring drug dealers or users they have arrested, police say. And detectives often end up using information from one drug gang to go after a competitor.

"You have to deal with the lowest scum of the earth," said one veteran D.C. detective. "You have to go down into the gutter with your informant . . . . To a vice cop, they're his bread and butter."

"It's a generally nasty environment," said Carl Klockers, a University of Delaware police affairs expert. "It's an environment of deceit and duplicity you wade in. It's extremely difficult to keep your sights straight . . . . You go native. You believe the whole world is filled by drug addicts, snitches and people of questionable virtue."

Detective Ron Robertson, a 17-year veteran of the D.C. narcotics unit, said a drug investigator has to keep his wits about him in dealing with informants. "A vice man starts getting himself in trouble when he starts developing a little rapport with a reliable source," Robertson said. "You should always remember that he's a source and it's strictly business between you."

The upside-down world of handling informants is a preoccupation for Robert Leuci, a former New York City narcotics investigator. In 1972, he acknowledged robbing drug dealers of drugs and money and giving drugs to informants. He then became a federal informant and helped indict numerous colleagues.

Leuci, who was not prosecuted in return for his cooperation, was the subject of the book and movie "Prince of the City" and now lectures to police departments nationwide, including the District's. He says he often sees investigators nodding in agreement as he delivers his lecture titled "Morality and Integrity Erosion."

"There hasn't been a cop born who's changed an informant," Leuci said in an interview. "It's the informant who changes the cop. They've been at it all their lives."

"Most cops have an ego and a macho" about their ability to control their informants, Leuci said. Often the relationship consists of elaborate mental games, he said, with a detective boasting to colleagues about how well connected his informant is and a snitch manipulating his police contact to his own advantage.

Inevitably, if they operate as equals, the street hustler will win, if only because the hustler has more money, Leuci said. He recalled times when he would get out of his beat-up car and into the El Dorado of an informant, who might have $5,000 in his pocket. "I'd barely have enough for a frankfurter. And he'd say, 'Here's $50, get yourself some lunch.' "

Having so much money readily available -- either from the drug dealers or from the department's undercover purchase fund -- can be tempting.

According to a confidential police department memo and to sources, the purchase price for information varies widely, and sometimes approaches several thousand dollars. D.C. police officials are considering establishing new guidelines for use of the department's "confidential fund," used in undercover drug purchases and to pay informants.

Because so many informants are drug addicts themselves, giving money to them can lead to officers ignoring the snitches' drug use, officers say.

"Informants want money real quick and you're how they get it," a D.C. vice detective said. "They want their money quick so they can buy junk. But I don't give a damn what he does after he leaves my car."

Fulwood echoed that thought, saying that locking up an informant for a minor offense could endanger a larger investigation.

While police administrators agree that informants sometimes need to be paid, many express uneasiness at the practice of winking at snitches' improprieties. That often leads to a morally corrosive atmosphere, they said. "Once the rationalization process starts, where does it stop?" said Murphy, a police affairs consultant to the U.S. Conference of Mayors.

Academics who study police corruption have identified a series of steps downward, from the seemingly harmless cutting of bureaucratic corners to the most coldblooded criminality. It is not known whether the pattern has developed in this way in the District.

Sometimes the first step is putting false information on search warrants, as it has been alleged in the 4th District case. That allegation prompted federal prosecutors last month to drop nearly 400 drug cases made by 4th District officers from January 1986 through last August because the prosecutors fear the officers lied under oath to a judge to obtain search warrants.

During his years as a prosecutor, Teslik said, he and his colleagues "suspected a lot of perjury" from D.C. narcotics investigators.

Teslik said one longtime reputed practice was for D.C. drug investigators to line up everyone in an area noted for drug activity, then take their drugs and throw them away. The practice is improper for many reasons, most prominent among them that the officers usually lacked the required "probable cause" to believe a crime had been committed.

"They were following a law of the streets, showing {the dealers} who's boss," Teslik said. Such officers were "the crusaders" who "didn't believe they should be subject to the same constraints as other officers," he said. Prosecutors "felt some of them were very dangerous. It was immaterial to them if they trampled on somebody's rights."

The next step, police officials say, may be taking money or drugs from one dealer and giving them to another, an informant. The officer becomes almost judge and jury himself, deciding which criminals should be prosecuted and which protected.

Soon the officers may rationalize using seized money to buy themselves new surveillance equipment or a new undercover car -- all in the name of better police work. These steps sometimes lead to the most serious kind of corruption, such as stealing drugs, money and weapons from drug dealers. But some officers rationalize even those acts as a kind of frontier justice that gets around what they see as silly rules that hem them in.

The 1981 film "Prince of the City" -- which closely followed the real-life events in the New York case and which has been shown in training seminars to drug investigators around the country -- showed a corrupt officer confessing to prosecutors. "I don't understand why you people don't understand the system," he said. "You want a conviction but you got these stupid search and seizure laws . . . . You want the big dealer out of business? The only way I know to push him out of business is to steal his cash."

However far the the corrupt officer may go, his colleagues most likely are noticing at least some of it, and that's where some of the worst problems lie, experts said. Under most departmental rules, failure to report improper behavior is an offense in itself. And many officers are reluctant to violate the informal police code forbidding informing on colleagues.

"You become implicated in that web," criminologist Klockers said. "It's like a plague."

Top D.C. police officials have a number of ideas to combat corruption, such as drug testing and financial disclosure requirements for some narcotics officers.

Fulwood also said the force must try to lower the tension among narcotics officers by such techniques as stress management courses.

"You're operating in a life-and-death environment," Fulwood said. "It's not something where you can make mistakes."